Head replacement.

[TSchulz]

So at the moment I am burning oil like crazy. Another forum said to replace the head but could not tell me why or what head to replace it with. Anyone here with any suggestions? Also other than head studs is there anything that I should do while I have the engine apart?

[cre]

I hope whomever you were talking to had more basis for that determination than you've just provided us.... Oil entering the cylinders could come from a large number of places (might not even be oil; a lot of people mistake excessive fuel for oil in the exhaust). Would you mind giving us more specifics? Which engine?

Turbo or N/A? Have you done compression and leak down tests? Are either the oil or coolant contaminated with the other? Anything that looks like chocolate pudding in the oil cap? Is the coolant caustic? Is there a significant amount of oil in the intake piping?

[TSchulz]

Sorry, its a 7mge na. I brunette about 3-4a quarts of oil a month. I haven't done a leak down test or compression test yet. But I did check the fluids and neither is contaminated with the other. There is no milkiness on the oil cap and everything looks pretty normal....it just burns the crapout out of oil that I can find.

[interested!]

Originally Posted by TSchulz

So at the moment I am burning oil like crazy. Another forum said to replace the head but could not tell me why or what head to replace it with. Anyone here with any suggestions? Also other than head studs is there anything that I should do while I have the engine apart?

Hi! Many moons ago I had a car to work on ( straight 4 cyl-8 vertical valves ) that was going through oil at an alarming rare ( 1 gallon a week ) , it seems that the oil seals on the valve stems had become carbonised and brittle and the oil was bypassing the seal and going straight down the valve stems.This can be checked by removing each spark plug and checking the condition , oily?-black? heavy carbon deposit?
This was cured by replacing the valve seals -in-situ - by putting each piston to top-dead-centre to stop the valves being worked on falling into the cylinder and changing the seals .A special tool was required to compress the valve spring(s) but overcame the need to remove the cylinder head -problem cured.
If you are doing this-make SURE -ALL the oil passages are covered to stop the collet falling down one of them -it happens no matter how careful you are!

[cre]

I have a hard time imagining a 7M that's even missing a few valve stem seals going though this much oil. Also, the 7M's a non-interference engine, pull the keepers and the valve drops in far enough that you're not going to even compress the spring enough to get the keeper back on it. You can use the rope trick to get it done but I don't recommend that to the novice... they tend to scratch and gauge things more than enough when the head is pulled and sitting nice and easily accessible on a workbench.

TSchultz, are you actually burning oil? That mush oil would create one hell of a smoke screen. My recommendation is that you start cheap and easy; Do a compression test (once dry and once wet) and see what that shows. Read the spark plugs (look to see if any given one looks worse than the others). Check the intake plumbing for signs of excessive oil. Inspect the PCV system and make sure there are not clogs and that it's all properly routed to the intake.

Are there no external oil leaks? Has the head gasket been changed?

[TSchulz]

Thanks for the advise guys. I had figured I would start with a compression check anyways so that just solidified that plan.

As far as smoking, it is not for sure. I know that's weird, my pickup did the same....was a big screen. But no, the supra does not smoke at all. I cleaned the block when I got it to make sure it wasn't leaking and it is still clean and is not leaking anywhere that I have found.

I know for sure though that I have been able to smell the oil burning when I shut the car off a few different times. Might start just investigating this weekend, ill update when I have info.

[cre]

Check in the inside timing belt housing for signs of oil, check for oil dripping from the bell housing, check for oil running down behind the lower rear timing belt cover by the A/C compressor. Has this engine been rebuilt? Post pictures of the spark plugs, if you're burning that quantity of oil it should show very readily.

Also try feeling along the top of the bell housing and transmission for oil. When the HG leaks oil from the rearmost passage it often runs along there and doesn't drip out until much further back and often not unless the car is moving.

[TSchulz]

Yeah, I know for sure that it is not leaking fluid, once again, because I would see it in the drive way. I am also not getting smoke. So I decided I'm just going to pull the engine out and rebuild it becuase I dont know if anyone has ever done any work to it. Which leads back to the first question, is there anything I should do to it while I have it out other than replace the head bolts with the arp head studs?

[cre]

Originally Posted by TSchulz

Yeah, I know for sure that it is not leaking fluid, once again, because I would see it in the drive way. I am also not getting smoke.

It's going somewhere. As I said, there are places where it may pool while at slow speeds and low oil pressure and just wait until you drive at higher speeds and loads before it pours out... If you're not burning it you're probably dumping it on the highway.

And sure there's more you should do... If you're pulling it to rebuild it then you might as well actually rebuild it. Strip it, get the head and engine hot tanked, measured for warpage and shaved if need be. If you want a metal HG make sure it's smoother than glass (not as big of a deal with a GE); If you're going composite you want a little texture for grip. Get the cylinder's checked for distortion, if they're straight just have it honed and install new rings. Have the head checked for cracks. Get the valve stems seals replaced. Replace the oil pump if you can afford to. New bearings, new timing belt, new gaskets. Sounds terrible but all in all if you do the bulk of the work yourself it shouldn't break the bank as long as nothing is significantly wrong (such as a warped cylinder requiring boring and new pistons). Go through the list and prioritize... I recommend you put the things that are going to be the most inconvenient do at a later date at the top of the list.

[interested!]

Originally Posted by TSchulz

Yeah, I know for sure that it is not leaking fluid, once again, because I would see it in the drive way. I am also not getting smoke. So I decided I'm just going to pull the engine out and rebuild it becuase I dont know if anyone has ever done any work to it. Which leads back to the first question, is there anything I should do to it while I have it out other than replace the head bolts with the arp head studs?

Hi! following cre's advise I would recommend checking the valve seating , reface the valves and seats if required , mine were very pitted and needed re-cutting .
My head was very pitted with corrosion and had to be welded and skimmed . everything you do at this point is always a good thing for ease of mind , preparation is 99% of a good job done.