What brand of M103 head gasket? - PeachParts Mercedes-Benz Forum

ps2cho · #1 11-17-2010, 09:19 PM

I am going to be pulling the head off my 300TE again over Christmas break and redo it since I am losing oil out the back.

I followed the procedure for torque..I don't really understand why it is seeping out there. I triple checked the valve cover, even swapped it out with another one with a new gasket and it still leaked. It was fine for about 5k miles then started leaking. I had the head skimmed and pressure tested so it still should be flat.

Do I need to purchase new head bolts after 8k miles since the replacement? I went with VictorReinz before...Should I go to the dealer and get the head gasket with them? What brand is OE?
Getting my part list together now....

Anything else I should do to make sure it does not leak this time around?
Thanks

Gilly · #2 11-17-2010, 09:30 PM

The head bolts are only replaced if they have exceeded the stretch limit, you need to measure them all and compare to what the max limit is. I've never had to replace one, but every one I have ever reused HAS been checked.

I recommend running a tap through each bolt hole in the block and running each bolt through a die, then soaking the bolt in oil for a short time before reassembly. After chasing the threads in the block you need to blow each hole out with compressed air. Remove the bolts from the oil and lay them on a paper towel to let the excess oil drip off. Then reinstall by hand and start the torquing procedure to the letter, never let an air tool touch a head bolt!

No idea on the head gasket, I was at a dealer so whatever the parts dept gave me, never had a problem like you are describing, not after doing the job.

ps2cho · #3 11-17-2010, 09:42 PM

Quote:

Originally Posted by Gilly

The head bolts are only replaced if they have exceeded the stretch limit, you need to measure them all and compare to what the max limit is. I've never had to replace one, but every one I have ever reused HAS been checked.

I recommend running a tap through each bolt hole in the block and running each bolt through a die, then soaking the bolt in oil for a short time before reassembly. After chasing the threads in the block you need to blow each hole out with compressed air. Remove the bolts from the oil and lay them on a paper towel to let the excess oil drip off. Then reinstall by hand and start the torquing procedure to the letter, never let an air tool touch a head bolt!

No idea on the head gasket, I was at a dealer so whatever the parts dept gave me, never had a problem like you are describing, not after doing the job.

Then I'm sure it is fine from such a short time being in there.

I'm hoping all I had was a bad gasket because I was pretty meticulous on my replacement...Possible block warp? I'll chase the threads for sure though thanks for the input.

Original thread: http://www.peachparts.com/shopforum/showthread.php?t=241701

Ferdman · #4 11-18-2010, 04:06 AM

ps2cho, the length of time the head bolts were installed has little relationship to whether they exceed the stretch limit. As Gilly mentions, it would be best to measure each one before reusing. Unless you want to risk doing the job a 3rd time.

Gilly · #5 11-18-2010, 04:42 AM

Correct, it takes what, 5 minutes to check the bolt length.

Gilly

#6 11-18-2010, 07:40 AM

Making sure that the machine shop checks the head for straightness is more important than the brand of head gasket.

When doing this job you should; check the head bolts as wisely mention earlier, have the head pressure tested, checked for straightness and a valve job including new valve guides. Unless this was done VERY recently, you should never take the head off one of these engines without doing all this.

Even in the case of recent head work, if you are changing a blown head gasket the head should be checked for straightness.

mbdoc · #7 11-18-2010, 08:19 AM

The OE gasket from MB is Elring.

OIL leaks at the front & back on the exhaust side can be from excessive oil pressure.

ps2cho · #8 11-19-2010, 10:46 PM

MB Doc -- Are there any oil gallery plugs or anything on the back of the head itself. I went back through my pictures and I don't have a shot of the rear.

Just wondering if its possible it is not the gasket, but a gallery plug or something on the head itself that could have been damaged when I had it dipped at the machine shop? Due to the tight fit, I cannot see well enough even with a mirror...

ps2cho · #9 11-24-2010, 11:20 AM

Also, does the OE gasket come as a kit that includes all the seals or is it gasket only?

Gilly · #10 11-24-2010, 04:16 PM

I believe you can buy it either way, a kit or just the head gasket seperately, more common to find it on the shelf as a kit.

duxthe1 · #11 11-24-2010, 07:11 PM

I've seen several head jobs leaking like you describe. We revised our procedure at the shop and use additional sealant in the front and rear corners on the exhaust side. The MB black silicone sealer will keep it from leaking. Apply very sparingly around the oil pressure passages making sure that it will not squish out into the oil pressure holes, both sides of the gasket.

ps2cho · #12 11-26-2010, 02:01 AM

Quote:

Originally Posted by duxthe1

I've seen several head jobs leaking like you describe. We revised our procedure at the shop and use additional sealant in the front and rear corners on the exhaust side. The MB black silicone sealer will keep it from leaking. Apply very sparingly around the oil pressure passages making sure that it will not squish out into the oil pressure holes, both sides of the gasket.

Sounds like a bandaid...There is a reason why it is leaking. I prefer doing the job right...

I guess I won't know if it leaking out the gasket or the (possible?) threaded oil plug on the rear of the head until I physically take it off again. Shouldn't be too long of a job this time around. Couple hours and I should have it off.

Again though, if anybody can confirm if there are any gallery holes in the rear of the 103 head that would be great.

ps2cho · #13 11-27-2010, 11:04 PM

Seems I am losing a little coolant too. Maybe it truly is the head gasket then? That or a warped block. Anybody ever had a warped block?

long-gone · #14 11-28-2010, 04:19 AM

I posted on this subject about a year ago..."http://www.peachparts.com/shopforum/showthread.php?t=258037&highlight=long-gone"

When I did my head gasket (91 300E @ c220K), just around the same time you did yours, I found that there were indeed differences in head gaskets. The gasket that came out of the car was an Elring (it had been replaced previously @ about 114K) I ordered a Reinz gasket set. The gasket that came with it had an extra line of red rubber beading BETWEEN the hole for the water jacket and the hole for the oil gallery (where the notorious leak occurs).

Without going into too much detail, when I first laid the head down I inadvertently scraped a small piece of the red rubber beading on the gasket. So, I got an indie shop I'm friendly with to overnight me a new gasket. It too had the mentioned modification, but it arrived damaged so I had them send it back and get another. The new one DIDN'T have the modification and was a much lighter colored material than the ones with the modification. The warehouse said that was the last single gasket they had and couldn't get any more, only head sets. At the dealership, they had only head sets as well, but they were Elring anyway and didn't have the mod. Long story short, I tried a few online places (including here) and couldn't get another Reinz gasket with the modification. I had four head gaskets at one point!
All the Reinz gaskets without the mod were a much lighter grey material and if I remember correctly the Elrings were darker as well, felt somewhat softer and I think maybe slightly thicker.
I ended up talking to a gasket design engineer at Victor-Reinz to try and track down this modified gasket. He wasn't [if I can recall] able to expound on the darker material or could he find anything about the extra bead between the holes. But he did feel that given the location of the area that I damaged (on the outside edge of the last oil drain hole) that I could get away with repairing the small portion that I scraped off with MB black sealant. Which is what I ended up doing.

Beyond the elusive modified Reinz gasket, here are some suggestions for you from my experience:
-- Use wooden dowels in a few headbolt holes to direct the head into place. If you don't, you risk scratching the soft aluminum head on the steel alignment dowels when trying to seat the head.
-- Do not over aggressively scrape or wire brush the block surface. Especially at the notorious leak area. Take as much time as you need to carefully scrape and clean the surface without marring it. If you use a wire brush on a powered tool, use a brass brush. And BE SURE to cover all cylinders, ports and openings to not allow flying wires from the brush to get in them! Do not use abrasives!
-- As suggested by others, meticulously clean the bolt holes. Use rags first to sop up the oil puddled in them. Then use carb/brake cleaner with a spray tube (wear goggles!) followed by cue-tips and then compressed air (if available).
-- Also as already noted, check the bolt length for spec (if not new ones). Lightly lubricate the threads and mating surfaces. Properly follow the torque sequence.
-- The new style headbolts (with thick integral flange-collars) do not use washers.

Be aware that the threads in the block can get stressed after a few head gasket jobs and do sometimes strip. I believe there is even a jig-tool for installing thread inserts in headbolt holes for M103/4 blocks. It's not common but happens enough that many Benz shops have the tool on hand.

ps2cho · #15 11-28-2010, 12:54 PM

Any ideas if this looks like the modified gasket?