meister_raul Posted October 22, 2020 Author Share Posted October 22, 2020 Hi. I am having some issues with my Toyota Supra and I want to get your opinion on this. -1994 Toyota Supra Auto jdm tt mostly stock -full decat, stock twins, k&n air filter, no major mods I had an overheating issue, I was new to Supras and overheated the car couple of times. I had an aftermarket temperature gauge who who showed more than 210 F but the original one never got past middle. I took the car to a mechanic who told me that the radiator cap was not holding pressure at all. I asked him to check the water pump and timing belt, he said all was fine. After this, I drove the car for a couple of months (it worked fine) and after it sat all winter. The car worked fine this year but the coolant started to get browny and couple of km after it started to ovearheat again. Coolant was dissapearing, there was a strange smell from the exhaust and the hoses didnt had pressure. As soon it overheated again I didn't drove it. Overheating occured especially when the car was sitting in traffic and had a slightly improvement at an open road. So I bought a blown headgasket tester (that thing with the blue liquid) and it seemed that I had exhaust gases on my coolant. So i took the repair manual and started to dismantle everything. BIG SURPRISE....the camshaft pulleys where not at the sign, they where with a teeth to the left and the belt was loose ::( I didnt got to the tensioner because I have to remove the crankshaft pulley first. Still, the car worked fine, it started fine and it only had a strange rattle when idling. ***The car was never raced, abused and i never did burnouts or things like that. So why did this happen? because of the wrong timing? Or the gasket was damaged from the previous overheating? Also,the headgasket shouldn't have any signs of damage? visibile one? I couldn't see one. Should I worry that gases get in water from another spot? I took the head to a specialised repair shop but they can't test it for cracks, should i test it somewhere else? Is it possible to have a damaged head? And if you have any other suggestions or tips about the headgasket replacement I am happy to read them ;) here are some pictures : [video]https://youtu.be/D5aC6bHhQwY[/video] Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 22, 2020 Share Posted October 22, 2020 Have you checked to see if the head is warped ? at the least with a good straight edge but better on a machine with a DTI verdict clock It's obviously got a serious issue if its lost coolant and has exhaust gas in the coolant Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 22, 2020 Share Posted October 22, 2020 210f is only 98c, they generally run at 90 degrees anyway so thats not really overheating, The gasket or head was almost certainly damaged from previous overheating event Quote Link to comment Share on other sites More sharing options...
meister_raul Posted October 25, 2020 Author Share Posted October 25, 2020 The head will be checked for flatness at specialized workshop. Should I also test it for cracks? I dont know if the aftermarket temperature gauge is reading good but water as boiling and coming out through the pipe from the expansion tank. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 25, 2020 Share Posted October 25, 2020 [quote name='meister_raul']The head will be checked for flatness at specialized workshop. Should I also test it for cracks? I dont know if the aftermarket temperature gauge is reading good but water as boiling and coming out through the pipe from the expansion tank.[/QUOTE] Doesn't need to be specialised, any engineering shop with a vertical mill like a bridgeport turret mill can do it, if you don't know how hot its really got then a hardness test is also a good idea. Contact Chris Wilson on here, use his email though as he doesn't use the pm system Quote Link to comment Share on other sites More sharing options...
meister_raul Posted October 25, 2020 Author Share Posted October 25, 2020 [quote name='Dnk']Doesn't need to be specialised, any engineering shop with a vertical mill like a bridgeport turret mill can do it, if you don't know how hot its really got then a hardness test is also a good idea. Contact Chris Wilson on here, use his email though as he doesn't use the pm system[/QUOTE] I will contact him, but why? I dont live in uk, how he will help me? Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 26, 2020 Share Posted October 26, 2020 [quote name='meister_raul']I will contact him, but why? I dont live in uk, how he will help me?[/QUOTE] Incase you wanted to ask an expert regarding the issues with your engine and the best way forward Quote Link to comment Share on other sites More sharing options...
meister_raul Posted October 29, 2020 Author Share Posted October 29, 2020 Could you please help me with his email? I can't find it anywhere Quote Link to comment Share on other sites More sharing options...
meister_raul Posted October 29, 2020 Author Share Posted October 29, 2020 UPDATE I removed the crank pulley and find out that the tensioner was jammed. I took the head from the repair shop and they told me they've cut 0,15 mm and my question is, what headgasket should I use? thanks. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 30, 2020 Share Posted October 30, 2020 [quote name='meister_raul']UPDATE I removed the crank pulley and find out that the tensioner was jammed. I took the head from the repair shop and they told me they've cut 0,15 mm and my question is, what headgasket should I use? thanks.[/QUOTE] How much was it it warped by ? more than 0.10 mm and its out of tolerance, also it needs to be tested for hardness Chris Wilson. Race and performance road car servicing and preparation in north Shropshire. Race and road car engine building and tuning. Suspension development and geometry specialist, Supra work and other cars too! 07971-952084 [email][email protected][/email] Quote Link to comment Share on other sites More sharing options...
meister_raul Posted October 30, 2020 Author Share Posted October 30, 2020 It was warped 0,15 mm. Should I put a headgasket thicker by 0,15 which means 1,45? Stock has 1.3mm and I think mine it's original, it doesn't have any marks Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 30, 2020 Share Posted October 30, 2020 In theory the head is scrap, if it was warped along its length then the cam journals will be out of line which you can't do anything about Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 2, 2020 Share Posted December 2, 2020 As Dnk says, measure along the bottom of the cam bearing saddles. ideally they should be in line within a couple of thou inch, but if it's been run a while like a banana and the cams haven't seized they have probably aligned themselves, albeit with some having a lot of clearance The head needs hardness testing to see if it's gone soft. I can do this. Don't waste time skimming a soft head, the gasket will just go again. It;s effectively scrap if it's soft. Stock gasket will be fine unless skimmed a LOT. Check for corrosion allowing coolant passages to have become enlarged and the gasket unable to seal them. Do the guides BY LINERING ONLY if it's off and usable, and the stem seals if you are keeping the thing long term. DO NOT replace the guides, you have been warned.... Quote Link to comment Share on other sites More sharing options...
meister_raul Posted December 26, 2020 Author Share Posted December 26, 2020 Sorry for not posting for a long time. Thanks for your reply. @Chris Wilson we talked on email a couple of weeks ago. Unfortunately I dont live in UK so you can't help me with the hardness test. I just found out the previous owner had overheating issues before (he didn't told me, I just found out in an old thread) so I guess that's why he sold the car a bit under the market price Now, that I studied the engine bay I saw a lot of wires and pipes that became hard because of the ovearheating over the years. This is how my head looks after being skimmed, those damaged water ports must be from runing water and not coolant i guess. My fear is that he has done the same thing as I want to do and there is a problem with the head. Is it possible that the headgasket was changed before? Could this be oem from factory? it has a hole in it and it looks exactly like the one I ordered, check my pics. I spoke to many mechanics who rebuild engines and they said the water ports are not so bad...well... Anyway I am very dissapointed. I've spend 400 euros just on the tickets to UK for a Supra that overheats. This happened in april 2017 and I drove the car back to my country, about 2500 km and it didn't overheated. It started to overheat when it became very hot outside, middle june. From the history of the car (the previous owner kept a jurnal) It seems that in 2014 changed radiator, water pump and thermostat. So I am guesing that's when it started to overheat. I also saw in his repair manual the following chapters and text marked: turbos, headgasket torque sequence, oil sump, cooling... I must be a detective to find out what happened before Overall, the car needed a refreshment because there where many pipes and wires that had to be changed, many seals and stuff to replace and clean. Merry Christmas guys! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 26, 2020 Share Posted December 26, 2020 (edited) Lay the head gasket on the head, if the corrosion does not encroach under the gasket it will be OK. The crack(s) in the wastegate seat are typical, you will be hard pressed to find used turbos that are not cracked. That crack is not severe and won't affect the wastegate sealing. The crack(s) will get worse though... Now, take the old head gasket, find the rivets that hold the laminations together. You can clearly see one of them in your photo. Drill them all out and separate the gasket into its laminations. Clean them all in something like petrol or cellulose thinners. Examine them all, especially the inner ones, under a bright light, flexing them. You may find an inner laminate is cracked. Often going between cylinder bores. It's common on NA's, less so on TT's. Outwardly, before splitting the gasket, it can appear perfect, but a crack in an inner lamination can and does cause overheating and / or water loss. If the gasket seems OK, check the block face is not warped. If OK get the head pressure tested by someone who knows how to do it properly. I'd estimate 90% of places do it wrong and will miss cracks due to their poor test method. Bear in mind some cracks only show when the head is at operating temp. Pray you don't have a head like that.... Make SURE the rad cap has not lost its none return pintle valve. If in doubt fit a new genuine Toyota cap. DO NOT fit a high pressure one or the next thing is you will be taking the interior apart to fit a new heater matrix as the abnormal pressure will rupture the tired old thing. Edited December 26, 2020 by Chris Wilson (see edit history) 3 Quote Link to comment Share on other sites More sharing options...
meister_raul Posted December 27, 2020 Author Share Posted December 27, 2020 @Chris Wilson Can't thank you enough for your help. You've been a real help for me! Fortunately I have a spare set of turbos who are in good condition and i've replaced the cracked one. But both of the turbos have radial play (more than acepted in the manual ofcourse ) Quote Link to comment Share on other sites More sharing options...
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