warped heads/head gasket - PeachParts Mercedes-Benz Forum

E_420 · #1 08-30-2007, 10:14 PM

So i've got a 1994 MB E-420 and i've needed a new head gasket. When I called the dealer and without looking at the engine they said in addition to the head gasket the heads may be warped. Which would double the repair cost if they are warped. Is this a commen or rare occurance?

Thanks

450slcguy · #2 08-30-2007, 10:20 PM

Common, like peanut butter and jelly.

nissanzx1 · #3 08-31-2007, 09:21 AM

You might try an independent repair shop instead of the dealer. This will be an expensive job and you can save hundreds by shopping around.

-GH

david s poole · #4 08-31-2007, 09:41 AM

if the heads are warped,i would be surprised if a good machine shop couldn't straighten them.they use a procedure that involves bolting to a jig and heating them up pretty hot and then a gradual cool down.

northshore · #5 08-31-2007, 10:12 AM

Quote:

Originally Posted by E_420

So i've got a 1994 MB E-420 and i've needed a new head gasket. When I called the dealer and without looking at the engine they said in addition to the head gasket the heads may be warped. Which would double the repair cost if they are warped. Is this a commen or rare occurance?

Thanks

Whenever a head gasket is replaced the cylinder head is almost always sent out to a machine shop to be milled down. It is routine.

G-Benz · #6 08-31-2007, 12:37 PM

Depending on the extent of the overheating that would have caused the gasket breach in the first place, milling isn't always needed.

But as said, independent shops can do this for far less than the dealership.

I was quoted $100 additional for the service (320, not 420 like yours). It turned out that it didn't need milling, but got the head components replaced or reconditioned. If the dealership opts to double repair costs, they'd should at the very least completely recondition the heads!!

This was mine after it came back from the machine shop:

E_420 · #7 08-31-2007, 01:55 PM

Thanks everybody for the info. It was greatly appreciated.

Kestas · #8 08-31-2007, 04:32 PM

Quote:

Originally Posted by david s poole

if the heads are warped,i would be surprised if a good machine shop couldn't straighten them.they use a procedure that involves bolting to a jig and heating them up pretty hot and then a gradual cool down.

This worries me, as I am intimately familiar with aluminum head metallurgy. This heating procedure could potentially overage the aluminum and take away a lot of the strength that was put into it by the heat treaters. Anything over 325°F is flirting with the metallurgical design of the head. Sure, the head may be straight after the procedure, but it could suffer long term problems afterward.

I say shaving the deck surface is the way to go.