Huffty500

Hi guys here's one for you im totally stumped! Ive got a 305tpi in England here and the other week I was on the motorway and the needle starteda climbing! I stopped at the services opened the hood, no signs of heat (cold water) so left it a bit and carried on. Didnt help though it got hot again, so carried on and had to get to the next services. By the time i did she didnt sound great so I had her trailored back home.

As i opened the bonnet to inspect there was some steam from drivers side cylinder bank. Underneath the car the water was pouring out (which is one of the core plugs that has gone) but it wasnt hot???

A week or so later when it was home i had to drive it to my garage. Only a short trip and the engine sounds fine. Problem again still getting hot.

Here's the wierd part... You'd think the water pump had packed up. Fitted a new one 6months ago, so i took it off and its fine all ok. I removed the thermostat and it was open. Although considering my temp needle for the whole time ive owned the car rarely moves off the bottom (unless in traffic) im assuming its always been stuck open.

Ive flushed the radiator and the block where the thermostat sits and the pump itself. Doesnt appear any blockages.

Now thinking back to my journey usually if you get hot, you put the heater on right? Well i did and it wasnt working. It had packed up.

Does anyone know the route of the coolant system on a tpi? All i can think of is a block inside the block?? I cant understand how a car can overheat (popping a core plug even) and NOT boil the water? something obviously went or got blacked but im stumped.

Sorry for the essay guys but can anyone suggest anything or show me a coolant flow diagram? Even if it's blocked tho the water would boil? I reiterate the pump is ok and the belt that turns the pulley was nice and tight, just cant get my head around this conundrum. Ok I should have changed the thermostat but this is just wierd. Dont want to put it all back together and fix the core plug and it still be knackered.

RiV

You mentioned your thermostat was open. Did you not replace it? Thats what you don't want ( a stuck thermostat in any position). Rather this advice is right or wrong, the thermostat is only supposed to crack open at 190 degrees and allow cooled water from the radiator to flow into the block and everytime you check one by removing you should have one in hand to replace it with since they are cheap. Along with the fans that turn off on, asuming you have electric fans, all this works together to maintain a temp(Not trying to sound condecending). I can't remmeber what time the ist fan kicks on but I think its close to 190 or 200 degrees..followed by a second fan that kicks on when you run the ac and/or the engine temp raises above 230 to bring it back down... thus the temp being maintained around 205-220. I'm sure these numbers are better defined it's just somthing to work with. Another thing is that these cars like to run warm so 220 degrees or less is what you want for a norm. Needle 1/2 way and climbing is time to think calmly, 3/4 is time to do something to correct.

So your left with the problem of cool water and a hot running engine. Well I honestly don't know for sure what you should do. Somebody else may need to chime in. But how did you test the water pump to know it was good? By your reasurance we'll move on. Maybe the stuck thermostat allowed water to flow through all the time and never have enough time to cool in the radiator proper. Maybe the water pump quit working and the water began to boil in the block due to the no flow and poped a plug. After it poped out came the hot water allowing the cool water to get sucked into the block from the stagnet radiator and replace the hot water as it ran out before you could see the situation.

Main thing is if you without a doubt know you have a good water pump, and have a new thermostat installed, as well as reinstalled a new block freeze plug, and had the cooling system filled again with the heater on high during the fill process. Allow the engine to warm up to normal temp and top off the radiator and put the cap on. Fill the coolant resevoir a little at a time to the hot line. Carefully(@ your own risk to nearby moving parts)Feel the main radiator hoses, it shouldn't be easy to pinch the hoses together with your finger and thumb (use just enough pressure to squish and egg in the same manner). IF you feel flow and temperature difference between the outlet and return hose then you should be fine. If this doesn't get you squared then wait for some one more knowledable than I am on cooling troubleshooting to post. It is very likley you have a clogged radiator were the bottom of it is cooler than the top. Somee radiators don't get much help from a flush even if you see water flow out. Might be able to feel the side caps of the radiator without getting knicked by a cooling fan as you feel up and down it. I suggest trying to feel the radiator on the passenger side. Good luck m8 I'll be checking back to see if youre having any luck.

naf

iTrader: (7)

Could this have started with the new water pump install a few months back? There are two water pump styles. Serpentine systems use a reverse rotation pump vs. the earlier standard rotation v-belt style.

Aside from that I'd pressure test your cooling system before going further. A blockage bad enough to prevent ALL the coolant from reaching the radiator should be pretty evident. The pressure test will rule out some other, hopefully remote, possibilities.

Tpx

Pressure test is an excellent idea, I second it. Also, go grab yourself a temp. gun, It was 50 bucks for me and has been invaluable to pinpoint hot spots or variation in temperatures in my cooling system. It should help show you where the water is cold and hot, thereby narrowing the problem down to something you can fix.

Huffty500

Cheers guys some great advice there (really appreciate it). The bit about warm water already being out and cold water then flowing out is a very good point made. I tested the waterpump by removing it taking off the back plate and spinning it. Used a garden hose with the back plate back on and got a mate to spin it. you can see when it spins the flow out the 2 back holes that would go into the block increase. The pump i know is ok. Thermostat stuck open = my bad. I'll admit i had one and neglected it. As for fans yes there's two of them the second i switch on in say traffic. Im thinking i might sell it because really i should change all core plugs which = engine out which = beyond my capabilities. Id be gutted if i paid the labour to have them fixed and it overheated again. Spent a bit on this car, Nos, borg warner rear axle ahhh i dunno. Is there anyway i can get a coolant flow diagram for the lb9? Pressure test is a good idea as is temp gauge.

88TATBI5.7

i stuck open thermostat wont cause over heating. its just like leaving a washer in there to restrict flow. takes longer to warm up but wont hurt anything. a quick check to make sure you water pump is still working is to take the raidiator cap of and look into your radiator. you should see a good amount of cavitation when the engine is running. if you poped out one of your casting plugs (freeze out plug) when you over heated you might have a major clog.
coolent moves from the waterpump through the main block by the plugs up through the heads into the intake and out through your heater core and thermostat neck. its a very odd problem but to me it really seems like your water pump is shot or a magor clog. just because it looks good the impeller can get loose on the shaft and not beable to move as much water. pressure testing will only show if you have a leak. sorry to say i cant think of anything to check for a magor clog.
also just so you guys know the thermostat starts opening 10-15 degrees before the rated temp. the rated temp is for fully open.

anyway good luck and keep us posted

Huffty500

cheers. Yeah the pump is defo ok no play in the shaft or sticking and spins no prob. When the needle started to go higher than uhoh point in traffic i switched the heater on (as you do to draw heat away) and it was hardly working. Only a bit at the windscreen vents. A clog would explain the cold water. As the gentleman above said the hot water could have dropped out and the cold uncirculating above then came out. I mean i say cold luke warm but definately not right. Its annoying coz as we know i cant just change one core plug ive got the set but that means engine out and if it still doesnt fix it then major ball ache. Ahh if i have to sell as spares or repairs i'll cry.

loneroad

iTrader: (3)

is there a spring in the bottom hose, the water pump can suck that hose flat and not allow any water to circulate.

RiV

Alright, everyone has made some good suggestions. The heater core could be clogged. (You should change the thermo stat out with a new one for proper cooling just for the reason that it makes the cooling and operating temp the way it is supposed to be) The coolant will never be really cold because it doesn't have time to exchange heat in the radiator if the thermostat isn't installed and working.. and eventually if you are in traffic it WILL over heat. It's an anomally and arguable but it's pretty much fact. Most people that say that not havign a thermstat installed makes their car run cooler when most of those people have engines that can function that way at speed ect, or they are making short runs to work or the market. It will affect what your ecm reads and how it directs your car engine to operate.(were not really that worried about that for this trouble shooting so forget about that. If it stays cold too long (before it finally begins to be become ineffeciant at cooling because the thermostat insn't installed)then it will effect other things that I won't list here.Mainly the computer times how long it takes to get to operating temp to kick the fans on ect once you start the egnine. All this stuff is programed and any alterations effect it's effeiceny at maintaing temp in ALL normal situations, aircondition blowing, not blowing, secondary fan blowing. Now, In my opinion you should reinstall the lone plug and move onto getting this car back on the road.


(very simple) spend 10 bucks or equivlant money from Erurope and an hour of your time to get back in the fun times of just driving your bird.-before you get too heartbroken and sell it.(knowing that you tied everything)

Fill your cooling system with some good radiator cleaning flush solvent from a local parts store(you mentioned you flushed already...respond if you havn't done this procedure to the letter), run the car up to temp WITH THE HEATER ON and let it run for 15 mins with the treatment(follow the instructions on the bottle) .. then shut off the engine and let cool for 30 mins. Carefully turn the drain tab on the bottom of the radiator on the passenger side and let it begin draining the garbage. May need some small pliars to turn the plastic tab gently at start but should be able to use your fingers with care to not let hot water just get all over you.. Start the engine again while thats draining and allow water from your garden hose to fill the radiator as it runs again for 15 mins WITH THE HEATER ON.(don't "shoot" streaming water in the radiator just keep a good pressure flow.. keep doing this until clean clear water runs out of the radiator drain plug.... and don't stop early just because it runs out clean earlier than that. Quite often does the water come out clean and then "splugs" out trash and run brown and green ect( or what ever color coolant your using) with rust. It will kinda go back and forth from clean to dirty. Do this until clean water constantly comes out.Keep an eye on your engine temp the whole time or have an assistant keep tabs on it. Don't be afraind to rev the engine some as this helps force the bad stuff out. Matter of fact I recomend you maintin 2000 rpms with periodic reving. Make sure you maintian the level in the radiator.

Now check for flow back into the radiator from the smaller tube near the cap. It should be. ALso while running the garden hose water into your readiator the whole time your engine should be running colder than normal or fluctuate from cold to warm, to mildly hot, so don't panic.

After all that and you are not getting flow into your radiator from the small tube by the radiator cap, then you proably have a major clog in your heater core or some where else and this proper flush has wasted your time until the next troubleshooting step. Try bypassing the heater core I post how to do that later.

Now some condensed points to follow by the heart.
1) Always keep checking the temp of your engine on the guages) have a helper
2)IF it gets way too hot during any of this(were u fear she's gonna blow "it's almost in teh red) then shut it down.
3)IF you have no flow at any point it will get hot and you will do number 2
4)IF the small hose going into the radiator isn't pumping in fluid at any time then you have a blocked heater core still. OR you have a definate blockage in your system some where, rather it be still in your core or in the block
5) IT's simple, follow the flush/treatment procedure on the bottole using my reference as a guideline. Either way it will work how it's supposed to. The run water until it's constant clean means run cold water into the radiator for as long as it takes. And engine reving and rpm maintinig REALLY does help blow that bad crap out of the system.
6) if You complete this, then you are well over half way at troubleshooting your problem.

If we have to do a heatcore bypass to get you using your car again then we will. God forbid you have a major clog in the block still.

Ps: I really do feel that you proably have a clogged heater core. And trash has also stuck open you thermostat. I firmly believe that changing your thermostat with a new one and changing it again after you flush the Whole system proper will reslove your over heating. The core may not be salvageable to have heat in the winter but, trying to flush again a month later may finally get some flow through it. In either case if you just won't flow through the heater core it's time to bypass it... Good luck and I'll be waiting for your update

naf

iTrader: (7)

Discount the clogged heater core. It will not stop water from circulating in your block. Your '87 should, in fact, have a vacuum operated heater diverter valve on one of the hot water hoses to the heater core that stops fluid flow to the heater when the HVAC temp switch is in the 'cold' position.

Symptoms still most closely match the installation of the wrong style water pump. Hope you've verified this isn't the case.

I'd recommend against using the plastic petcock on the bottom of the radiator to drain it, unless you're willing to pull the radiator out and replace it. That 20+ year old piece of plastic probably won't survive the job. Just pull the hose.

You've got to pull the motor and replace your freeze plugs. Flush the block out then. If it's clogged it will be readily apparent.

RiV

naf is right. I merely wanted you to try and fix more than one problem with two quick fixes. The flow from the small hose into the radiator would show he did have circulation in the system correct? Just not ruleing out proper flow through the block. I would have told him to pull the big return line for flushing but it would have been harder for him to maintain fluid level for the flush calmly. Thoughts? My reasons are they are cheaper and more satisfying to know you have done all before doing the big job of pulling the mtr.