Slowridr

iTrader: (1)

I have had my intake gasket replaced twice.

1st time when I had someone replace my injectors.

2nd time to stop intake leak at rear of intake.

Well its leaking again! Now on the passenger side maybe 3/4 the way back. This is getting expensive and I think Ill just do it myself this time. The guy that did it the 1st 2 times was suppose to be very experienced having worked for a Chevy dealer years ago when these cars were new.

I need to know what to use to stop this once and for all. Its getting old and expensive!

Im pretty mechanically minded so I can figure things out just figured I could get it done quicker by paying someone thats been there before.

Let me know

Slowridr

iTrader: (1)

Or

While Im at this I'll switch the TPI setup I have on my LB9 with this one. Im going to take it off and clean it up very good and maybe paint it.

I want it to look stock.

Any reccomendations on that?

ASE doc

Having done a multitude of chevy intakes, I have developed the following procedure.

First buy only Fel Pro gaskets. Cheaper brands will only bring us greif.

Drain coolant as much as possible by opening drain on radiator. Its good to also open block drains if you can raise the vehicle. However, since block drains are generally inaccessable with the vehicle on the ground, and there is no other reason to raise the vehicle when replacing the manifold, I generally skip the block drains. Be aware, the better you drain the coolant, the less coolant youre going to have run into the crank case when you pull the manifold. You will generally get some anyway. When removing manifold, keep track of fastener location. The manifold bolts are often different lengths and having locations right will be vital when reinstalling.

Clean head and manifold surfaces carefully, I use a yellow nylon surface prep wheel in my 90' die grinder. If you dont have this option, use a scraper and finish with a single edge razor blade. Be careful not to gouge or score the surface, especially aluminum. When done scraping use a scotch brite pad for a final cleaning until you are confortable that all foreign material is removed. Then degrease all sealing surfaces with brake clean to insure good adhesion. Use a shop vac to remove all coolant traces and cleaning debris from the cam valley. Do one last visual to be sure everything is right. Anything you overlook now will bite you later.

Before installing the new gaskets, test them for fit, some Fel Pro intake sets have alignment notches to help in installation, see if yours do. Make sure they go on straight and fit well. Next, apply a small bead of "Permatex Ultra Black" around each of the 4 coolant passages. I use my finger to flatten these beads to insure good sealing against coolant leaks. Extend these beads down to the front and rear end seals to protect against oil seepage. Install the manifold gaskets on top of the sealant beads being sure to align the bolt holes with the matching holes in the gaskets. Once the gaskets are in place, apply a thin bead around the coolant passages on the gasket the same way you did on the head surfaces. Again, extend these beads down to the end seal ridge on each corner. Then, using "Permatex The Right Stuff" apply a heavy bead, about 3/8" thick along the front and rear end seals, creating a good heavy seal against oil leaks at these areas. Be sure that the end seals youve just created make good contact with the manifold gaskets at each corner. A little overlap has never hurt me.

Now comes the tricky part. Carefully lower the clean, dry manifold onto the gaskets. The straighter you are, the more assured you are of a good seal. The idea here is to get the fit right the first time so you dont have to move it around too much. A little adjustment is to be expected. Having to raise and reposition the manifold on the gaskets and sealant compromises the integrity of the seal. If you think youve really screwed it up, remove the manifold and redo it with new gaskets and sealant. Better to do it right away when the sealant can be wiped of with a cloth than to wait til its hardened and has to scraped of. When youre satisfied that the seal is good, install the clean, dry fasteners by hand assuring that the threads are fully engaged. Before installing the bolts, apply teflon thread sealant to the 4 front and 4 rear bolts on each side as these bolts enter the coolant passages. Then following the torque sequence which should come with your Fel Pro gaskets(the only brand worth using), tighten the fasteners in several steps working your way around, gradually seating the gaskets and sealant. Tighten bolts to 17-19 ft lbs.

The reason for the 2 different sealant products is that Ultra Black is softer and will work better to seal around the coolant passages. The Right Stuff is stiffer and will create a stronger end seal.

After youre finished, pack up, clean up and let the vehicle sit overnight (allow sealant to cure) before adding coolant. I generally dont have this luxury at work but love it when I can let one sit overnight. This is an excellent final step towards assuring a lasting seal. Always change engine oil before starting the motor following intake manifold replacement. Some coolant will have run into the crank case and you dont want to run your engine on oil, coolant mix. NOT GOOD! Fill system with new 50/50 coolant mix and bleed air from system. If you have the thermostat out, drilling a 1/16" hole (if it doesnt already have a bleed installed) in the thermostat, between the sealing edge and the valve seat, will assist in bleeding the cooling sys.

Good luck and, enjoy.

ASE doc

Like my previous post wasnt long enough, the 4 intake manifold bolts closest to the center of the motor on the TPI system are at an offset angle (more vertical than the other bolts. These should be the first ones you install and you may have to run them down a little before the remaining bolts will line up. Take care aligning and installing the manifold bolts that you dont cross thread any.

Slowridr

iTrader: (1)

Now thats how you answer a question!

danziger

ASE doc- That reply should be included in a sticky somewhere...good stuff!

Slowridr

iTrader: (1)

I agree that description is Money!

I think your signature belongs there too. That is universal.

Chevy86 IROC-Z

iTrader: (17)

ASE Doc, Well said.

Slowridr

iTrader: (1)

OK here is how I came to this conclusion.

I noticed oil by the starter. I initially thought it was my dip stick leaking at the motor. There was also oil on the oil filter. So pressure washed everything down yesterday.

Got up this morning to see if it would leak without car running. Pulled starter off and No leaks.

So I cranked car up and began looking for leaks. I had car on jack stands so I could slide in and out easy.

Car idled for about 5 mins and nothing, so I reved car up. Looking at the back around the distributor and such. Figured it had to be in the middle to get oil on both sides.

Then I started looking at the intake as far toward the front as I saw oil. Then I noticed the area in the pic. I noticed it had no sealant squished out.

Then I looked under car again and noticed I started to get a couple of drips. Looked at the transmission and noticed a steady stream of oil down the front edge of the tranny where the dust cover fastens (dust cover off). Saw another drip forming and edge. This is passener side. This is where most of the oil ends up.

Jumped back up top an looked at that area then took a screwdriver and did what I showed you in the pic. Got fresh oil on it. Couldnt really see a steady stream coming out but did notice wetness in this area.

Reved engine while holdnig flashlight there and saw misting of oil. Could it be coming from somewhere else? Possibly. But it sure looked like it was shooting oil from that gap in the gasket in the intake. Im no expert so I could be wrong here. It was a steady misting when the engine was reved.

Slowridr

iTrader: (1)

Here is the pic of the fresh oil on the flat head screwdriver. I took it from the area in circled in pic one where it looks to me a section of the gasket is out.

jstoltz

iTrader: (16)

I normally use indian head sealant on the gaskets too but yeah the right stuff is the best I have found for end seals. or use indian head on the cork seals but the right stuff is the way to go in my opinion. good luck also did you ever have the intake checked out to make sure it isn't warped?

Slowridr

iTrader: (1)

Never thought to do that. I will be switching intakes so maybe that will resolve that problem if its a factor.

jstoltz

iTrader: (16)

figured I would throw it in there never know if it was overheated. Good Luck.

Orr89RocZ

iTrader: (20)

Right Stuff is awesome. I have used it on alot of my motors. Infact, I didnt even use a fel-pro intake gasket. I used pure right stuff as the intake gasket material on all over the head and block deck walls. Worked like a charm.

I may also add to let it set up for a few minutes before final torquing of the manifold bolts. Let it set up for a few minutes, put the manifold on, lightly hand snug the bolts down, then let it setup for a few more minutes. When it starts to feel abit tacky, torque them down. Worked the best for me.

marc12321

i use felpro gaskets. i dont put gaskets on the front and back i put a nice bead of locktight orange gasket maker. never had a intake leak problem

ASE doc

Right on about letting it set a few minutes before final torquing. I always snug down fasteners where I know I have complete sealant squish, then let it set up for some time before final torque. Letting the whole thing set up overnight before adding any fluid has served me well also. Havent ever tried the no gasket deal, but if it works for you then what the hay? BTW, I love, love, love, that sweet twin turbo setup! Read through your build thread. The technical perfection of your work is what I strive for everyday. The turbines poking through the hood is sick and sinister. I bet it sounds like jesus come early too.

ASE doc

BTW, That last message was meant for Orr89. Sorry to hijack the thread. Slowrider, my brother. It is hard for me to concieve that an intake gasket would leak in that area. However, Ive learned to never say never. But, look closely at the leak. Are you sure its not from the valve cover? Your buddy would have had to remove at least one valve cover to R&R the manifold. Its common to displace the silicone valve cover seal during installation. It could be manifold, the oil would have to be traveling across 1.5" of gasket to get there but anythings possible. If it does end up being manifold, let's make sure your PCV system is functioning properly. Excessive crankcase pressure can cause some crazy leaks.

ASE doc

Oh, and to answer your other question, Accel makes the Super Ram TPI base and TPIS makes the Big Mouth. Both are diect bolt on replacements for the stock TPI base and have largeer ports for increased flow. Talk to me about how to build a high horsepower, high revving TPI system using either of these pieces. And alot of other really pricey parts. LOL

Slowridr

iTrader: (1)

I changed the valve covers last week and was very careful when placing them back down. Thats where I thought the leak was to begin with.

Do yall think I should take it somewhere and get some more opinions before pulling that intake?

ASE doc

It might not hurt to get another opinion. One problem with helping each other on TGO is that we only get pictures to look at, not the actual car, in person.

Thanks for clarifying the valve cover issue. Do be sure to check PCV system. Sounds like you may be getting high crankcase pressure. Good call on checking intake for warpage. Should look real closely at fit and for any obstructions too. Two leaky intakes in a row makes ya wonder if theres not an underlying issue.

Good luck bro

Slowridr

iTrader: (1)

Guys I did a 210mi round trip cruise yesterday with a local F-Body club and didnt leak any oil!!!!! I didnt do anything different to the car. Didnt leak a drop!!!

What I did notice this morning when I checked my oil was that the CCV I think its called was out of its hole in the passsenger side valve cover. I noticed some folks on here saying check to make sure there is no back pressure from the pcv and maybe thats what is causing the oil leak.

How do I hunt done a blockage in the vent system. Just change the CCV and PCV? I called for a CCV at some local parts stores and none said they have it have to go to the dealer. Let me know what you think given these new developments.

ASE doc

Hey slowrider, The CCV(Crank Case Vent) or make up air tube, as I know it. could very well be cogged. This is part of the PCV system I recommended you check out.

The PCV system operates as follows: During idle or high vacuum conditions, the PCV valve is open and crankcase gases are drawn into the intake manifold and mixed with intake air to be burned. Fresh air is drawn into the engine through the make up air tube which draws air from the front of the trottle body.

During high throttle openning, low vacuum conditions, the PCV valve closes and crankcase gases are drawn into the intake manifold through the open throttle to mix with intake air and be burned.

So you see, even if the PCV valve itself appears okay, its important to be sure that the rest of the PCV system is okay. Because during acceleration, the PCV valve doesnt even do anything. Its the make up air tube that vents pressure.

Check the port at the throttle body where the tube connects. Its probably coked shut with deposits. Check the entire system for any restrictions and - just to make your friend, ASE Doc, happy - replace the PCV valve, theyre cheap.

Good luck

Slowridr

iTrader: (1)

I changed that PCV valve it made all the diff in the world. It virtually stoped leaking. I only have a few drips every now and again. Not sure how much Im gonna worry about them. The engine is over 20 yrs old. Im gonna keep an eye on it though. Ive got a 500mi round trip cruise with the Power Trip coming up next week Ill see how it goes then.

I can tell you this. Ive driven over 400 mi since last Sat and it hasnt leaked down any noticable amount when checkig the oil dip stick.

ASE doc

Cool beans! Have fun bro. I am so jealous. My beasty baby sits under the awesome car cover my woman bought me for christmas. Havent driven her since last summer. I start her every few weeks just to listen to that sweet and brutal rumble and roar. Soon though, real soon shell be back out scaring the natives.

Slowridr

iTrader: (1)

Hey Doc have a new issue now.

This is starting to drive me nuts.

I am now leaking coolant. Its leaking from the back of the engine on the pass side. It drips right on the exhaust pipe where the 2 pipes off the manifold come together and a little behind that.

Ill probably have to wait until Monday to give a good strong look at them but what could leak back there. Heres what I am figuring

1. Freeze plugs
2. Heater hoses (going into the heater core)
3. There is 1 other thing-a-ma-bob back there too (I think it goes into the intake)

Let me know what you think I should look for.

I also thought about the head gasket but would I not have oil and water if that was the case. This is 100% antifreeze (AF) and its very clean not rusty or oily looking.

Also I am not getting AF on my floorboard on the pass side. I would think that rules out the heater core.

It seems to gush out and then it just drips after I turn off the car (maybe 1/2 - qt of AF.

What say you?

ASE doc

Hey Slowrider, What a drag huh? Sudden leaks like this are usually a failed hose. Gasket leaks tend to come on more gradually. Youre right to assume its not head gasket. External head gasket leaks are rare. Im confused as to what "two pipes" your referring to. Are they AIR pipes(air injection reaction) from the AIR pump?

At any rate, the most likely culprit in your case is the heater hose that connects to the rear right corner of the intake manifold. Trouble is, Im not where I can look at my 87 and I cant remember for certain if your engine has this hose connection.

If it does, then its just to the right of the dist (left side when viewed from the front). If it doesnt have this hose then the next most likely cause of the leak is the right rear corner of the intake manifold. Aaarrrggghhh!

There is a coolant jacket at each corner of the manifold, each of which is sealed by the manifold gasket, as I referred to my manifold reseal instructions. If not properly sealed when the intake is installed, any one of these four coolant jackets can leak.

Thats why Im such a **** about the use of the correct sealant.

To find a leak in this area is way too much fun. Again youll need a mirror(the kind with the swivel head and the telescoping handle like a big dentists mirror) and a bright flashlight.

You can run the motor to pressurize the cooling system, but its much better to use a cooling system pressure tester. With the system under pressure, use the mirror and flashlight to look at the seam where the manifold, cylinder head and engine block all come together.

This can be a real pain as there is no clearance and the area is covered with harness conduit. But if the manifold is leaking there, youll find it this way.

Needless to say, we both hope its the hose.

Good luck my friend, Doc

Slowridr

iTrader: (1)

Our power went out so I had nothing else to do but play with my car. Took all of 5 minutes and found the anti freeze leak. A hose coming out of the heater core at the fire wall had a hole in it.

Whenever there was enough pressure the AF would shoot out a steady stream from this hole.

If all the problems with these cars were so easy to find and fix.

ASE doc

Excellent news my friend. Happy cruising.

Doc

Slowridr

iTrader: (1)

Doc how well do you know wiring. In changing this hose I found 2 or 3 wires that are not connected to anything. They seem to come off of the main harness. I am going to get some pics up when I get to it late today.

Maybe you can help shed some light on this for me.

ASE doc

Post a photo when you can. Also wire colors. They may be grounds.

Slowridr

iTrader: (1)

Ok here goes Doc.

1st wire is just a small tan wire-no stripe. It has been spliced together by someone maybe it was cut at some point. It is located just behind and a little to the left of the distributor. It goes into the main harness from the ECM there.

2nd wire is just a green wire-no stripe (a little heavier wire than the tan one) it has a single male connector on the end. It also goes into the maoin harness from the ECM in the same place as the tan wire.

The 1st and 2nd wires seem to naturally lay on the passenger side of the distributor.

3rd wire is a double wire (I guess I should actually call this a connector) it has 2 wire going into a double male connector. One wire is pink-black stripe and then the second wire is black. It goes into the main harness from the ECM behind the distrubutor on the drivers side. It seems that this wire wants to lay naturally to the drivers side of the car.

The 2nd pic I was just trying to show where the 2 wires entered the harness.

Now for some background. This is not the original engine to this car. It is an 1987 LB9 car and currently has an 1988 L98. The L98 came with its original harness but I am not sure what the guy that put in the car used because as you know the 87 and 88 harnesses are diff. Plus the 88 is serpentine and 87 is both serp and v-belt. I see a lot of splicing so I am guessing he used the 88 harness.

I also noticed some codes from my ECM after I added a Catalytic Converter before that 250mi cruise. It only threw codes on interstate driving after about 15 mins of driving btwn 70-80 mph.

After I finished changing the hose and drove it around for about 20 mins got another SES. Got home and checked codes and had a 13 and 32 codes thrown. Those are O2 sensor and EGR respectively.

Let me know what you think.

I am not going to stress to much about these unless you say I should. I would prefer to not have this happening so if I can get this rectified I would like to. But I really want to do this cruise to Charlotte on Wed. Its 500mi round trip.

Slowridr

iTrader: (1)

Edited Pics

ASE doc

Hi Slowrider, I have some info that should make you feel better. The tan wire is most likely O2 sensor ground. This would explain code 13. The green wire with the weather pack connector is probably the EGR temp sensor. Your engine may or may not have this sensor. If it does, it should be located close to the EGR valve and will have a lead coming from it that will connect to the green wire. If your vehicle doesnt have this sensor, then you have another issue with the EGR system.

I assume this is the first time the MIL has been on while driving. You havent mentioned before. I trust that youll find the EGR temp sensor unplugged and that connecting it will solve code 32. Check these things and let me know. Ill try to get you going for the 500 mile cruise.

ASE doc

BTW, I cant recommend driving the vehicle for any extended time with either of these codes.

The EGR(exhaust gas recirculation) system recirculates a small amount of exhaust gas(which is mostly CO2) into the intake air stream during cruise conditions. The inert gas dilutes the intake charge lowering combustion temperatures. This reduces the production of NOX(oxides of nitrgen), a pollutant gas. The reduction of combustion tempuratures also prevents valve damage which may be caused by lean fuel mixtures and is made more likely by todays oxygenated fuels(10%methanol).

The purpose of the O2 sensor is self explanitory. If it is not working properly. The ECM has no way of managing fuel mixture in closed loop. Without long and short term fuel correction, there is no way of correcting a lean or rich condition. Rich condition will destroy your new cat. A lean condition will destroy your new cat and your engine.

Slowridr

iTrader: (1)

Wow

Ok I guess I need to get to it then.

Ill have the hood open early tomorrow.

Can you tell me where to look for these. Ill also grab my Service manual and start looking too.

Slowridr

iTrader: (1)

Any thoughts?

Man i am having a hard time figuring this out.

ASE doc

If your service manual has a decent diagram of the "Engine Computer Control Circuits", these components should be in that diagram.

As for locations, the EGR pressure sensor should be at the base of the EGR valve. Its a single wire coming out of a small metal base, looks like a tiny O2 sensor. It should have a connector that will mate with the green wire.

The O2 ground goes to the back of the right cylinder head.(left as viewed from the front). I have also seen this ground attached to the rear right bolt on the manifold(again left as viewed from the front). Look for a matching wire terminal with the wire broken off. You will need your mirror and flashlight for this.

As far as connecting the ground to the engine, you may need to lengthen the wire by splicing a length of wire to it. Use a butt connector if you must but be aware that this is a low amp, low voltage ground circuit and it should be soldered and protected with heat shrink tubing.

Butt connectors do not provide a good long term connection and you may have trouble with it in the future. However, if you do a good job with a butt connector, you should be fine through the next year or two.

I never did find the pink/blk and blk wires with connector in my diagrams. I tend ot think that they may have been used for some accessory. Gm generally seperated their engine control harnesses from their accessory and lighting harnesses. But I could not find it anywhere. Pink/blk is ignition power. The black is ground. Repair the O2 and EGR circuits. If the MIL stays of, dont worry about the other wires for now.

Slowridr

iTrader: (1)

I saw where a ground connector on the back of the right cylinder head was broken off. there is also a strap from the body that seems to b connected there as well.

Why cant I just ground this anywhere.

I also found the EGR pressure sensor. It looks as if a piece is broken off of the end of it. Give me 5 mins and Ill get a pic of it.

Slowridr

iTrader: (1)

I just noticed this regarding the connector that we think is a ground.

These go into a square connector that comnes out of the main harness on the drivers side of the car. It appears that someone cut the tan wire and brought it over to the passenger side for some reason.but if I hold the tan wire together with the tan wire sticking out of the back of that connector it matches up perfectly so Im calling this the correct place for the wire. tan wire comes from that same main harness that runs behind the engine.

I cant seem to put the pics here

heres a link to another thread id started asking the same question. With pics


https://www.thirdgen.org/forums/elec...ml#post4586824

Slowridr

iTrader: (1)

I think you hit it on the head with the Egr pressure sensor. Can it also be called egr temp sensor. Mine is broken off it still has the end sticking in the base of the egr valve. I assume that I am looking at the correct thing under the plenum?

Napa parts

http://www.napaonline.com/Search/Det...+50060+2060012

ASE doc

In the square connector where you have found the tan wire the other wire should be purple/white. This is cold start injector drive. Please dont connect your O2 ground to this. It may be hot with 12v and will toast your ECM. Its probably dead but its still not a ground.

The O2 ground is connected directly to the engine in order to provide it the cleanest ground. Connecting it anywhere else may not work as well. I am confident that if you reconnect your O2 ground and the EGR sensor, your engine will be fine. The codes will go away and if your car has been starting okay, you dont need to worry about the start injector wirng right now. Either the installer powered it some other way, or you dont need it.

Slowridr

iTrader: (1)

Heres a pic of that wire. Ill go check it now since I dont have my cold start injector hooked up.

I will not connect those 2 together.

That wire coming out of the back of that square connector is definitly not purple. Its tan just like the wire I 1st showed you.

Slowridr

iTrader: (1)

Is not the cold start wire the one on top. I looked at the injector there at the manifold and it seems to be the one that fits.

The top connector also is the same as the other injector connectors thats along the drivers side of the car.

Slowridr

iTrader: (1)

Is it possible to get to that egr sensor w/out taking the plenum off?

ASE doc

Of course, youre correct. The top connector in this photo certainly is the cold start injector. Darnit, I recognize that other connector too but I cant remember what it is. And please forgive me. Ive been working on so many of these EGR systems on TB cars and didnt even think of the valve being buried deep under the plenum. Can you see the wire I was referring to? The pigtail that the green wire should connect to?

If you can see that it is certainly disconnected, Then try putting the two together using long nose pliers or forceps. Sorry if I cause confusion. Im old and slow. LOL

Slowridr

iTrader: (1)

Sometimes I think I cant win with this car.

Went to wash it tonite and my alternator is now reading low. Around 10 or so amps (I think thats what unit that gauge reads).

Its usually above or just below 13.

Surley these other problems didnt cause the alternator to act up did they?

ASE doc

Actually, the dash gauge reads volts. I dont think the wirning bugs youre dealing with right now would affect that. They certainly wouldnt cause your alternator to fail. However, from what Ive seen of your vehicle's wiring so far, I would not rule out wiring as the cause of your new problem.

Here is a quick test of your alternator wiring:

With the key off, test for 12v at the large black and orange wire(may also be red) which is connected by a nut and post to the back of the alternator. It should have battery power all the time.

Test for 12 volts at the small red wire in the connector that plugs into the rear side of the alternator. This wire should also have battery power at all times.

If these circuits test okay, remove your alternator and take it for testing. AZ tests parts for free.

Im still working on that square connector. I will try to figure it out today.

ASE doc

Hey slowrider. Think I found our mystery connector. How is your IAT(inlet air temperature) sensor connected? Im thinking the installer cut the tan wire and spliced it to a different connector. I remembered that this was the same issue Ive run into on a few TPI swaps.

GM changed connector styles for the IAT about 87-88. Some cars got one style some got the other. Your harness has the square style and the installer made a quick fix. Ill bet that your IAT has a rounded connector and that the tan wire is spliced to it.

The IAT is hard to see. Its threaded into the underside of the plenum towards the rear. You may be able to see it with a mirror and flashlight. I remember all too well how hidden it is as I have installed plenums and forgotten to connect this little sensor. Connecting it with the plenum on is way too much fun.

Slowridr

iTrader: (1)

Nothings wrong with the Alt.

Just checked it. My high output fan motor and air cond running caused the draw down of volts.

When I turnd both off the output went back to normal.

ASE doc

Good news. You may want to clean your battery terminals in any case just to ensure good contact. Voltage shouldn't drop that low with engine running, even with those loads on.

Did you get to repair your wiring yet?