M38 head gasket

baios · Post by **baios** » Sat Feb 08, 2020 2:06 pm

Please is it dificult to change a faulty head gasket on my M38? Find a water while changing my oils

Post by **wesk** » Sun Feb 09, 2020 12:48 am

For someone who has never removed a cylinder had it can be quite difficult. So it is not possible to tell you what the level of difficulty will be for you to change a cylinder head gasket unless we know your level of mechanical capabilities or experience.

If you are a reasonably experienced mechanic then it should not be difficult at all. Just follow the directions in the manual.

baios · Post by **baios** » Sun Feb 09, 2020 1:26 am

From 1to 10 i Will say 5

so i have the manual so i Will follow the steps. But what is suprised me is that my M38 has only 1500miles on it from my restoration.

soo propably my mechanic put a faulty one or

What else...

Post by **wesk** » Sun Feb 09, 2020 2:36 am

Water in the oil can be caused several ways. Leaking head gasket, leaking bolt threads, block cracks. Since you mention only 1500 miles since overhaul begs the question was the correct installation procedure followed including a re-torque of the head bolts after an initial short run-in period.

baios · Post by **baios** » Sat Mar 07, 2020 7:31 am

what is yr opinion???

baios, I took the liberty of reducing the file size of your photos.
If you review our wbe sites photo posting rules you will see theri 1.5 to 1.8 Megabyte file size is well over our 250K file limit. Wes K Moderator

Post by **wesk** » Sun Mar 08, 2020 12:00 am

Other tahn some localized severe corrosion I really can't see any other issues. It would be easier and more accurate to offer an analysis of the condition of the block deck & head after they have been properly cleaned.

I see you have a large puddle of antifreeze in #4 cylinder. Did you neglect to drain the block before removing the head or was the antifreeze already flooding #4 while the engine was being operated?

To convert your photos to an acceptable size I had to open a photo album for you here on our web site. Please review the attached links to posting rules and how to advice.

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baios · Post by **baios** » Sun Mar 08, 2020 12:48 am

Thanks i will follow your advise.

Now i drain the antifreeze from the radiator only.then i started to open
the head and i saw that antifreeze on 4 cylinder. Did i make a mistake in sth?

Post by **wesk** » Sun Mar 08, 2020 2:46 am

If the head removal was only for minor gasket or valve work then since you did not drain the block thru the petcock on the right side of the block you now must change the oil and flush any antifreeze from the oil pan. Also then you would know for sure how that antifreeze got on top of #4 piston. By draining the block before pulling the head you can avoid any liquids being trapped in the head and released the instant the head becomes loose. This way the presence of antifreeze in the #4 bore would indicate it was leaking into that bore while the engine was operating.

baios · Post by **baios** » Mon Mar 09, 2020 5:15 am

Here is some progress

But... I m afraid that i have the wrong head gasket .....althought a Greek dealer told me that is the correct

Post by **wesk** » Mon Mar 09, 2020 8:00 am

The gasket looks to be correct.

I see you did not have a machine shop clean and prepare your block deck and cyl head face for their refit.

Have you straight edge checked both surfaces for trueness? To insure all leak sources are sealed you must remove all your studs and clean threads and then install all the studs with sealant on their threads that thread into the block.

Did you remove all the valves and clean and inspect their faces, stems and seats?

baios · Post by **baios** » Mon Mar 09, 2020 10:34 am

ok im happy that the head gasket is correct althought from one side is aluminium and a mechanic told me that maybe it will not seal very well. the other side is permenite which is good sealant.

checked both surfaces seems very good. trying to remove all studs but the most of them cant move at all.

anyway i will go on and see

Post by **Ryan_Miller** » Mon Mar 09, 2020 2:55 pm

Don't forget to re-torque the head bolt nuts after the engine has warmed up too!

Post by **wesk** » Mon Mar 09, 2020 8:19 pm

For the head studs that seem frozen in their threads first you try continually soaking them with penetrating fluid for a few days and if that doesn't work then use a torch to heat them red hot. Clean the threads afterwards and test fit the studs. If they are loose in the block's threads then buy new studs.

baios · Post by **baios** » Thu Mar 12, 2020 1:47 pm

i have a little problem. need yr help

one stud isnt tightening correctly. i try to tighten it but doesnt stop nowhere.

i look the threads both in block and in the stud seems good.

i must make in a shop a new one because it isnt also straight and that makes me problem putting the cilinder head

the new stud must i make it with the last threads little conical at the end so to be tightened

Post by **wesk** » Thu Mar 12, 2020 8:21 pm

The course threads at the top of the photo came out of the block. Those threads are actually the threaded insert that ripped loose from the whole in the block.The insert or what is often called a "helicoil" was an earlier repair to the threaded hole in the block that has failed. Not only do you need a new stud, you also need to determine if the block is repairable. I suggest this is a job for an automotive machinist.