[Firestorm91tt]

As some of you may already read on a previous thread, I was having smoking issues coming from my catch can (all the time) and exhaust (under and after hard acceleration)

I am thinking of pulling the head and seeing if there is a glimer of hope something fairly simple in there is to blame vs. the rings being shot to hell on cylinder #4, since the psi was 110, while all the others were appox. 160 psi plus. Also, I noticed that my boost which was set at 19psi has for some reason jumped to 28psi and I havent touched anything on the boost controller. Would this kill a ring(s).

My question is what exactly am I looking for when I remove the head. Will something stick out and be quite obvious. I was thinking maybe the head gasket could be screwed as well since now I noticed I have lost a tad bit of coolant.

And as far as actually removing the head...is there any tricks to the trade or is it a strait forward procedure?

I hate asking all these questions, but with no search feature available, Im kinda at a loss.

 

[JRMSupra]

im fairly new to these engines, but i just got done tearing down my block, well still in the process. when i took the head off, you basically have to have everything pulled apart, including the timing belt, intake, exhaust, wires, fuel injectors, coils, everything!!

http://www.97supraturbo.com/1997 Service Manual/Engine.pdf

this may help some. Sorry if this is not really helping your problem.

 

[supradupaflyguy]

well, you sould be able to see on the headgasket if a piece is missing between that cylinder and a coolant passage, but honestly i think pulling the head would be a waste of time to just "look around", find a boroscope if you just want to look. try doing a leakdown test and then put some oil in the cylinder and see if it makes it any better, if it does its most likely rings, if not is either a hole in the piston or a stuck valve, listen if its coming out of the intake, exhaust, or crankcase. to check for a headgasket, get the coolant test kit which tests for combustion gasses in the coolant.

 

[Smaay]

you should also do the water hose mod while you have the head off. it cleans up the engine bay

 

[JRMSupra]

What is the water hose mod if you dont mindme asking?

 

[Firestorm91tt]

I went to a couple parts stores and asked for a coolant test kit and each time the store employees looked at me like I was smoking crack. Ill give it another go later today.

 

[98mkiv]

28psi will cause detonation and burn a hole in your piston. Though if that happened you'd have no compression on that cylinder. Sounds like your gate is either stuck shut or lost the reference pressure signal. 110 psi isn't so low that something catastrophic (piston hole) happened yet, but it could be a bad ring or valve.

 

[Firestorm91tt]

I went and did another compression test and this time added a bit of oil to the top of the cylinder by way of the spark plug well. Pressure went from 110 to 155 in a heartbeat so I am thinking Ill bite the bullet and replace the short block. I really need to get deep into this car and learn the ins and outs as I did with my Stealth and VR-4. Just a bit hesitant about pulling the engine/tranny.

 

[98mkiv]

I don't think you're heading in the right direction. You could have a valve that is not sealing well.... especially if you have a bad stem seal because the oil that leaks down gets cooked to the valve on the seal surface sometimes.

Before you get a new anything, pull the head. You'd be doing that anyway even if you're going to wind up getting a new block.....

Pulling the motor is cake by the way, much easier than you'd expect.

 

[supradupaflyguy]

I don't think you're heading in the right direction. You could have a valve that is not sealing well.... especially if you have a bad stem seal because the oil that leaks down gets cooked to the valve on the seal surface sometimes.

Before you get a new anything, pull the head. You'd be doing that anyway even if you're going to wind up getting a new block.....

Pulling the motor is cake by the way, much easier than you'd expect.

the general rule of thumb is if you add oil to the cylinder and the compression goes up (in this case 40 psi) its the rings, oil will not affect an open valve.

 

[supradupaflyguy]

I went and did another compression test and this time added a bit of oil to the top of the cylinder by way of the spark plug well. Pressure went from 110 to 155 in a heartbeat so I am thinking Ill bite the bullet and replace the short block. I really need to get deep into this car and learn the ins and outs as I did with my Stealth and VR-4. Just a bit hesitant about pulling the engine/tranny.

if you want the "inexpensive" way out, you can just replace the rings... you would have to pull the head and oil pan off, pull the 1 cylinders piston/connecting rod out, rehone the cylinder and install new rings and throw it back together. yes, granted this is the "easy" way out and some may say dont do this because there could be problems. but im guessing your motor has quite a few miles on it anyways so this could just be a temporary cheap fix until you decide you have bigger plans for the car. honestly if it were me and it was just rings that were bad, i would just replace them and see how long the motor lasted, if the rest is all good its a shame to throw it all away for something simple like rings. in the end its all up to you