Replacing the headgasket

[MountainDew]

Well if anyone saw my other thread, I was having problems with lots of smoke at high boost.

I got a leakdown and compression test done tonight.. 170psi on 2 cylinders and ~120 on the others. So I guess it's time for a new headgasket.

Basically is there anything I should keep in mind while doing this? I'm hoping to get the parts ordered by tomorrow. For parts I'm thinking MLS headgasket, ARP studs, cylinder head gasket set and getting a valve job.

If my rings are worn when I pull the head, can I replace them with the bottom end still in the car?

If I come to find out my head is warped should I look for a new one? Or get it milled?

Any tips or advice would be appreciated. This is a first time thing for me, and I want to get it all done right so the car will last.

 

[SnowBird]

NO. You could replace your rings with the head off and engine still in the car, but to properly do it I dont think you could easily hone the block with out risking hitting the crank. Replacing the rings really is more of a job than it seems, to check all the clearances and do the proper prep I think it would be a royal pain in the ass to even consider trying.

I just rebuilt my engine for the first time a couple months ago and it was tedious enough with a bunch of room to work. I havent checked your mods, but if you are running stock turbo or boost under 18 psi i wouldnt see the need to get a mls head gasket or arp's right away, with compression numbers like that I would just pull the engine and do the rings anyways.

 

[wilddog]

Replacing rings is tedious work, and may require machining and such. I would recommend pulling the motor (Its ALOT easier than it sounds). And while its out, you might as well spend some more money and have it built, along with replacing all the standard components, water pump, gaskets, etc.

 

[95blackGsTurbo]

Pulling the rods/pistons while everthing else is still in the car and honing the block is the #1 halfass way to rebuild a motor. Depending on the milege of the car you are going to need to bore the cylinder, check the main/rod bearings, rehone the main bore, and get the block decked to ensure it's straight. Just throwing new bearings in with new rings and honing it is NOT the way to do it. Take it out and do it right or don't mess with it at all.

 

[olmytsi]

Just remember that metal headgaskets require a near perfect finish on both sides to seal. You will have the head taken care of since you will send it out but the block won't. It may not seal. For that, i always recommend a stock headgasket. It's known to handle 30+ psi with the correct tune and it will seal for sure if the studs are properly torqued and the block is cleaned up by hand.

 

[MountainDew]

Yeah I think I'll just stick with the OEM headgasket.

As far as a full rebuild.. I just don't have the money, nor the equipment to pull the whole motor.

 

[JaxTalonTSi]

Yeah I think I'll just stick with the OEM headgasket.

As far as a full rebuild.. I just don't have the money, nor the equipment to pull the whole motor.

MountainDew,

Check out this thread I responded to a while back with sombody asking about a re-ring with the block in the car. I have done it quite a few times with great results, but you need to be carefull.

http://www.dsmtuners.com/forums/showthread.php?p=50403972#post50403972

I think the major issue right now is determining WHY your compression is so low on the cylinders in question. You can't just pull off the head assuming it's the headgasket, nor can you just pull out a piston, eyeball the bore and rings and say "yup, looks worn". A blown headgasket will often show obvious symptoms (overheating, bubbles in coolant, oil in coolant/coolant in oil, pushing coolant into overflow, ect.). If you don't experiance ANY of these symptoms, look a little closer into the problem before you start tearing things apart.

As far as your parts, DO NOT use a MLS headgasket unless the engine is being pulled out and machined. Sure, you won't ever blow that gasket, nor will you ever be able to get it to seal either. The deck of both the head and block surface need to be perfectly straight (RA60 or better). So just get a factory Mitsubishi headgasket set with composite gasket, and new headbolts if it's a 7 bolt (or headstuds if you want to).

 

[MountainDew]

MountainDew,

Check out this thread I responded to a while back with sombody asking about a re-ring with the block in the car. I have done it quite a few times with great results, but you need to be carefull.

http://www.dsmtuners.com/forums/showthread.php?p=50403972#post50403972

I think the major issue right now is determining WHY your compression is so low on the cylinders in question. You can't just pull off the head assuming it's the headgasket, nor can you just pull out a piston, eyeball the bore and rings and say "yup, looks worn". A blown headgasket will often show obvious symptoms (overheating, bubbles in coolant, oil in coolant/coolant in oil, pushing coolant into overflow, ect.). If you don't experiance ANY of these symptoms, look a little closer into the problem before you start tearing things apart.

As far as your parts, DO NOT use a MLS headgasket unless the engine is being pulled out and machined. Sure, you won't ever blow that gasket, nor will you ever be able to get it to seal either. The deck of both the head and block surface need to be perfectly straight (RA60 or better). So just get a factory Mitsubishi headgasket set with composite gasket, and new headbolts if it's a 7 bolt (or headstuds if you want to).

Yeah my buddy was telling me about the whole headgasket thing.

And I'll look into your thread, thanks man.