1993 300D - New Head Gasket? Leak in the Manifold - PeachParts Mercedes-Benz Forum

BullGator2020 · #1 06-04-2014, 04:34 PM

After replacing and installing 2 turbos, since I thought the turbo was the issue.

Under the advisement of some great knowledgeable folks from the this forum, I removed the exhaust manifold to see if the ports were leaking to rule out the turbos were bad. Guess what!

After pulling it out, it appears that ports 1 - 3 were all filled with oil. So does this indicate a head gasket leak? Valve Leak? Both?

Is there any DIY links to how to do this?

Will I need to take the the head to a machine shop?

Also, since I am going to go through replacing the gasket, what else should I do in this area since I will have all the components off?

(Links to any replacing would be helpful)

Off the top of my head here is what I am thinking:

- Clean and Paint the Exhaust Manifold
- Replace Exhaust Gasket
- Replace the Valve Seals
- Replace the Glow Plugs
- Clean, paint and clean all over the area

Thank you all for your help and keeping my dream of running this car alive.

jt20 · #2 06-04-2014, 07:52 PM

Check your inbox. Way too much instruction for this type of communication.

Read the manual and highlight specific questions.

Valve stem seals are mostly pointless if the valve stems are worn. If you're past 200k miles, the engine will perform much better with a full valve job. Plus, these valves are really difficult to free up without special tools or a homemade press.

You won't know if you "need" to bring it to a machine shop until you pull it off and check it for flatness.

You could do lots "while you're in there".... it gets expensive fast.

What's your budget?

How many miles on the engine?

97 SL320 · #3 06-04-2014, 08:58 PM

Valve seals and a valve cover gasket are inexpensive to purchase, changing them only takes somewhat time consuming labor. New seals will help even with worn guides and is a good first step if you are unsure how much life is left in the motor.

I've changed valve seals on dozens of engines with good results.

ROLLGUY · #4 06-04-2014, 11:47 PM

Quote:

Originally Posted by 97 SL320

Valve seals and a valve cover gasket are inexpensive to purchase, changing them only takes somewhat time consuming labor. New seals will help even with worn guides and is a good first step if you are unsure how much life is left in the motor.

I've changed valve seals on dozens of engines with good results.

Have you changed the valve seals on these with overhead cams and buckets? It is not an easy job, especially with the head on, or for the novice mechanic.

97 SL320 · #5 06-05-2014, 08:26 AM

The only additional difficulty for a bucket type system is removing the old seal and that does not change if the head is off.

There are tools to compress the spring, this is a tube with slots cut in it so you can compress the spring and extract the keepers.

There is a u shaped grabber that will pull off the old seal. You can also use a small sharp chisel from the top to split the steel body of the seal. If it is a one piece rubber seal, the grabber will pull them off.

If you are able to change one, you will be able to change the others.

And, at the end of all this, if you can't get the first one off, just continue with head removal. It is worth the risk.

BullGator2020 · #6 06-05-2014, 12:20 PM

Thank you so much John. My vehicle is a 1993 300D 2.5 Turbo Diesel (W124 - 602) with 210K miles.

My budget is tight under $1,000 for parts. I am trying to do all the labor myself to save on money.

So I should go ahead and replace the valves, seals, etc...?

What else should I do?

Glo-Plugs?

What special tools do I need?

jt20 · #7 06-05-2014, 12:37 PM

For $1000, you can do a rather thorough job "while you're in there".

Figure around $600 for the head if you find that it needs a valve job. There are some simple tests in the garage you can do to help make an educated guess on this. But at that mileage it may be in your best interest to rebuild the head while its off.

I agree with 97sl320, this head design is not prone to wear out valve guides excessively and the valve stems seals are definitely in order. I am quite certain you could do a really simple home-based repair without any shop work - if the head is flat and the engine has been well maintained. The engine will work just fine without a head rebuild. It all depends on your standards, what you want out of the vehicle, and your budget.

You have a budget that will allow you to rebuild the head and tackle many maintenance items along the way.

It is more than likely that you need a new headgasket. Above all, at this mileage, it is time to replace it, even if the valve stem seals are the source of the oil leak. This is a common task for these engines.

Start looking at all the stuff on the front of the engine. Vacuum pump, belt tensioner, injectors, water pump, hoses, lifters (buckets, tappets)

What history do you have of the vehicle?

What is the state of all those parts?

Its more likely that you will familiarize yourself with these items as you go along... not a bunch of us yelling out random failures we've all experienced. You are the only one with access to the car, you will have to make that call.

BullGator2020 · #8 06-05-2014, 12:51 PM

Just to make sure, does oil have to be in the coolant system for it to be a worn head gasket? Or does the oil in ports 1-3 of the manifold suggest that? What originally started my suspicion of the oil leaking in the exhaust was a failed turbo, but I have tried to install 2 supposedly working turbos and now the oil is in back of the turbos leaking out 5 quarts at a rate of 3 mins.

Here is what I know about the major repairs to the vehicle:

New Glow Plugs around ~120,000 miles.

Repair to the Wastgate ~130,000 miles

Replaced the Evaporator ~ 160,000 miles

Replaced the Radiator ~ 170,000 miles

There is no history that I know of to indicate the seals, gaskets or anything else major has been repaired.

I really appreciate all your patience and guidance. Also, I do really well with pictures, so if there are any links to "How to"s for the stuff above, it would be greatly appreciated.

jt20 · #9 06-05-2014, 01:21 PM

Thats a lot of oil. How did you verify this?

Dipstick levels vary quite a bit before startup and after shutdown.

That much oil is not likely the result of bad valve guides. Sounds like the head should come off and further inspection needed.

Check out the DIY links section. You can reference engine work on the om603 - it is nearly the same engine with the same problems.

BullGator2020 · #10 06-05-2014, 01:24 PM

Basically, I had a puddle of oil literally dripping out of the exhaust. Then when I checked the dipstick it was at the high mark before, and then it was under the low after. So about 3-4 quarts of oil in a matter of minutes. Its like it just ran through. The only visible leak was at the mainifold connection to the turbo. Than that is when I tool off the manifold as you suggested and saw the ports 1-3 with oil.

So once I take the head off, what am I looking for to indicate the source of the problem? Is it noticeable?

Maxbumpo · #11 06-05-2014, 01:44 PM

Quote:

Originally Posted by BullGator2020

So once I take the head off, what am I looking for to indicate the source of the problem? Is it noticeable?

I would imagine there should be a easily identified "trace" across one side or the other of the head gasket. I suspect that it must be totally blown out, so REALLY obvious. If any doubt exists, take the gasket to the shop that will work on the head, they should be able to "read" the gasket for you.

I'm very concerned that you may have hydro-locked one or more pistons, with all that oil, which would mean bent rods and more $$$. Once you have the head off, you'll need to measure the piston heights when each is at top dead center. I've never done this, so you may have to research what tools are needed and the proper procedure.

ROLLGUY · #12 06-05-2014, 10:06 PM

I believe the only source of that much oil is the turbo oil feed tube. The way to test it is to remove the intake and start the engine. If you have copious amounts of oil coming out of the cold side of the turbo, there is your problem. If you also remove the exhaust downpipe from the turbo, you should see oil there as well (it would not be getting there from the intake). I doubt the valve seals can pass that much oil, and the engine still run. Besides, turbo engines have positive pressure in the intake tract, and the seals try to keep boost pressure out of the crankcase. Bad valve seals in a turbo will cause so much blow-by, that you would notice it. I doubt you need to pull the head. Just my $.02......Rich

97 SL320 · #13 06-05-2014, 10:46 PM

Quote:

Originally Posted by BullGator2020

Basically, I had a puddle of oil literally dripping out of the exhaust. Then when I checked the dipstick it was at the high mark before, and then it was under the low after. So about 3-4 quarts of oil in a matter of minutes. Its like it just ran through. The only visible leak was at the mainifold connection to the turbo. Than that is when I tool off the manifold as you suggested and saw the ports 1-3 with oil.

So once I take the head off, what am I looking for to indicate the source of the problem? Is it noticeable?

If this is really happening, you have a cracked piston. There is no way you can get enough oil to go past valve guides for this to happen that rapidly.

You will need to do a compression test / leakdown test before going any farther.

ROLLGUY · #14 06-05-2014, 11:25 PM

Quote:

Originally Posted by 97 SL320

If this is really happening, you have a cracked piston. There is no way you can get enough oil to go past valve guides for this to happen that rapidly.

You will need to do a compression test / leakdown test before going any farther.

That much oil can't get in the intake from a cracked piston IMO. The air is moving through the intake (higher than the intake ports) so no or very little oil can flow upstream against the air flow. Also, the intake valves would be closed when the piston is in it's upward stroke. It would also have enough blow- by to force oil through every gasket and seal in the engine. Removing the intake and downpipe and starting the engine will rule out a bad turbo, but I can't think of anything else that would cause that amount of oil to pass through the intake manifold and out the exhaust.

sixto · #15 06-06-2014, 02:11 AM

Remove the injectors and crank the engine. I'm sure you'll see oil squirt out the first couple of cylinders confirming a fresh set of valve stem seals won't fix much.

Sixto
MB-less