To warp or not to warp....

[Alex C]

OK, so we all know by now that I have at least one blown headgasket. But are my heads warped? What are the symptoms of warping?

 

It still runs fine, no loss in power or anything else.

 

Alex

[Snowman]

Warping basically makes it so that a new HG will blow again in short order. Below a certain limit there are no ill effects since the gasket can compensate. If it's been overheated a lot, a warped head is possible. The only way to check is to remove the head and stick a straight edge on it.

[idosubaru]

if your headgasket is blown, why are you worried about it being warped or not? no way to check that with the head on the car. if you're replacing the head gasket then you should have the head checked and milled. it will most likely be out of tolerance, but well within the limits of milling. i find it unlikely your head is trashed, but it won't be perfect. ideally you should have it milled and have the cracks between the valves repaired (all EA82 and ER27 heads i've pulled had them). you can skip repairing the cracks and you can skip milling the head, each is added risk to the life of the engine and not milling is added risk that your new head gasket won't hold.

 

driving around on a bad headgasket is not good for your block. i had a leaking head gasket in one of my cylinders and just kept adding water/coolant all summer because like you said "it ran good". didn't take long to develop a massive knock in the engine. more than one knowledable person informed me that water in the oil will do a number on engine bearings.

[Alex C]

well, im replacing the gaskets this weekend, Im just hoping its not warped so I can forgo the milling, as I dont have time to do it. I am very reliant on my car.

[idosubaru]

headgaskets aren't terribly horrible to replace so if they do leak again it's not the end of the world.

 

if you're not milling, i would pay particular attention to the bolt threads, be sure they are clean and the bolt holes in the block are clean. some people recommend a little oil on the threads to alleviate friction and get a good tight torque on them. but not so much oil that it's dripping and running down over the gasket. be sure to retorque them if required. make sure all mating surfaces on the head and block are squeaky clean. i wouldn't cut any corners on these points if the head isn't milled.

[Snowman]

some people recommend a little oil on the threads to alleviate friction and get a good tight torque on them. but not so much oil that it's dripping and running down over the gasket.

Some people do. Like the Factory Service Manual:cool: . (At least for the EA82).

[Alex C]

Thanks, i knew about the oil trick, actually I was going to go with anti seize this time around. and a good torque wrench.

 

Alex

[85Sub4WD]

Anti-seize is probably a better choice. Actually you can get different tightnesses of a bolt whether you don't lube it, lube it with motor oil (or 3-in-1) or with grease. If you don't lube it you will undertighten it and blow the gasket again. If you use grease you will overtighten it and crack the head. Most all torque values for all cars assume the components are lightly coated in motor oil. That gives you the right amount of torque (and in this instance anti-seize is an even better idea).