Blown head gasket!!!

[ffedge]

Well I have a 99 cobra with 140k and today I noticed coolant leaking from the passenger side of the motor tonight, and I really could use some tips on how hard it is to tear the thing down and replace the gasket myself instead of takin it somewhere. I'm 100% sure its the gasket and if anyone has a write up on how to replace it I would be very thankful!

PLEASE HELP! Thank you.

 

[RedRocketMike]

Has the engine gotten "hot" at all?

 

[REX-RACER]

I don't know that actually changing out the head gasket is any different than any other engine. The complicated part, I would guess, is going to be getting the valve timing right again on the DOHC heads.

 

[ffedge]

Has the engine gotten "hot" at all?

the engine itself has not gotten hot, but the leak has been creating some air pockets in the system when the coolant gets low.

 

[ffedge]

I don't know that actually changing out the head gasket is any different than any other engine. The complicated part, I would guess, is going to be getting the valve timing right again on the DOHC heads.

do you know if the engine needs to be pulled? or can you do his from under the hood?

 

[Hi-Hat]

Just hope its the gasket and not the block...reminds me of my damn Camaro...that little shit!...

 

[REX-RACER]

do you know if the engine needs to be pulled? or can you do his from under the hood?

I can't speak knowledgeably about it but there are people here who can, you'll just have to wait for them to wake up and read this tomorrow. Everything I've seen on this sort of thing though w/ these cars involved the engine being out of the car.

 

[01rdcobra]

You can do it with the motor in the car and don't worry about the timing. Just set it on TDC and mark your chains, or you can just turn the crank until you line up the the dots on the sprockets with the ones ones on the chains and thats your cam timing. Its not that hard doing it in the car its just uncomfortable.

 

[chevysRslow]

Wondering if it's faster to just pull the motor... Anyone gone that route?

 

[VirtualSVT]

Wondering if it's faster to just pull the motor... Anyone gone that route?

Its faster if you have the facilites to pull the motor IMO.

 

[CobraKalas]

and while your at it, get the heads ported!:rockon:

 

[ffedge]

does anyone have torque specs for the heads or any other specs i will need?

 

[01rdcobra]

Get yourself a Chiltons' book that has all of the torque specifications. If you are pulling the motor get some studs instead of the TTY bolts. Get some longtubes also.

 

[na svt]

Studs are only needed for high boost motors and they do not allow you to remove and isntall the heads with the engine in the car, stick with bolts.

 

[na svt]

You can do it with the motor in the car and don't worry about the timing. Just set it on TDC and mark your chains, or you can just turn the crank until you line up the the dots on the sprockets with the ones ones on the chains and thats your cam timing. Its not that hard doing it in the car its just uncomfortable.

I suggest you should degree the cams while you are in there. This way you know they are installed where they should be and you can pick up some free hp. If you pull the engine it's much easier to do this also.

 

[Torch10th]

I haven't seen this posted yet so it might be worth a try before you go yanking the motor.

At 140K the engine has seen quite a bit of use. Over time bolts will work themselves loose, especially when heat is involved.

You may want to simply try to re-torque the head bolts.

You didn't mention anything about smoking, or foamy oil, so it's possible the gasket is still sealing the combustion chambers. Try to re-torque the heads and give it a couple days and see if the leak stops. If it does, great, if not then go about pulling stuff apart.

 

[ffedge]

I haven't seen this posted yet so it might be worth a try before you go yanking the motor.

At 140K the engine has seen quite a bit of use. Over time bolts will work themselves loose, especially when heat is involved.

You may want to simply try to re-torque the head bolts.

You didn't mention anything about smoking, or foamy oil, so it's possible the gasket is still sealing the combustion chambers. Try to re-torque the heads and give it a couple days and see if the leak stops. If it does, great, if not then go about pulling stuff apart.

Well it's not smoking, but there is a slight green tint to the oil on the dipstick and it leaks a tad bit of oil on the same side it's leaking the coolant from. But thanks for the advice on tightening up the heads! I'll try that tonight.

 

[RedRocketMike]

Well it's not smoking, but there is a slight green tint to the oil on the dipstick and it leaks a tad bit of oil on the same side it's leaking the coolant from. But thanks for the advice on tightening up the heads! I'll try that tonight.

Don't count on that working. You probably have a bad spot between a cylinder and a coolant passage and are getting exhaust pressure in your antifreeze, causing the air pockets. And you have a break through going out of the side and letting antifreeze letting it leak out the block.

At this point you have everything going for you; no antifreeze in the oil and you haven't gotten the engine hot and warped the heads. Drive this car as little as possible. And atleast send the bad head out and have it pressure tested and checked to see if it needs decked. If it does need decked get them both done. If you aren't very mechaniclly savvy I doubt this is a good job to do by yourself.

 

[elyrain]

If you have the $$, you may want to get at least valve job while the heads are out. Or like others said, any portwork or header install is alot easier to do at the same time.