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1993 500E
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142 Posts
Discussion Starter · #1 ·
I have a 1992 300SE with 91,000 miles that has a mysterious problem, according to my mechanic. Two weeks ago I found oil in my coolant reservoir and the oil in my engine was down about 2 quarts. There was no coolant in the engine oil on the dipstick. I called my mechanic who suspected it was a head gasket. I was disappointed because he had done the headgasket 14 months earlier. So, he went ahead and replaced the head gasket and he tested the oil cooler. He just called me and told me after putting the engine back together and flushing out the system, he is getting the same issue...oil is somehow entering the coolant and the engine oil level on the dipstick is showing about 2 quarts less. He is baffled, I'm not very happy, and I'm hoping someone here has had a similar experience and can shed some light on the problem. The engine is the M104 and has been running fine, no overheating. my mechanic suspects that something suddenly happened to either the cylinder head or the engine block and is hesitant to tear the engine down again to try and chase a bad cylinder head.

Any ideas out there? I would appreciate any insight.

Thanks,

Eric
 

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2000 C280, 2006 E350, 1993 400E, 2007 SLK55 AMG, 1994 S500, 2008 E320 Bluetec
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685 Posts
Have you been using synthetic oil? Have you recently run any sort of additive through your fuel?

Has your mechanic checked compression? Did he look at the plugs?

If there's a pinhole leak in the block below the compression point, I'd suspect a fouled plug and a shot block.

At this point, don't pour any money into the issue.
 

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1993 500E
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142 Posts
Discussion Starter · #3 ·
Have you been using synthetic oil? Have you recently run any sort of additive through your fuel?

Has your mechanic checked compression? Did he look at the plugs?

If there's a pinhole leak in the block below the compression point, I'd suspect a fouled plug and a shot block.

At this point, don't pour any money into the issue.
Have not been using synthetic oil or any additives. The engine seems to run fine, no missing. I'm assuming he looked at the plugs as he was also doing the 90,000 mile maintenance while he did the head gasket.

Mechanic has offered to put in a used motor for 2k, supposedly with only 30k miles. Other than this the car is a cream puff. Should I get a new motor, or is there something else that can be checked?
 

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1992 300SD, 1986 300SDL, 1995 E420
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884 Posts
Did he get the head machined? Could be there is a crack somewhere on the head.
 

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1992 300SD, 1986 300SDL, 1995 E420
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884 Posts
While he is in there make sure to replace the timing chain guides so you don't gotta worry about those.
 

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1993 400E
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7,361 Posts
I just checked my WIS and there is a listing of "oil in coolant" in the complaint index. Cause: oil cooler defective. #5



 

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Premium Member
1998 140.070 CL500, 1966 406.121 U65
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1,489 Posts
Here is the part drawing of the oil cooler (not that many has it);
Êàòàëîã

br,
syljua
 

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'14 E350, '07 CLK350, '01 SLK320
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I just checked my WIS and there is a listing of "oil in coolant" in the complaint index. Cause: oil cooler defective. #5
The OP mentioned that the oil cooler had been tested. What puzzles me is that the oil always seems to go down by the same amount. I would think if the cooler or some similar pressurized component was bad it would keep pumping oil out until the low level warning light came on. This doesn't seem to be the case.

I'm at a loss. Maybe you should cross post this issue over at mercedesshop.com There are a lot of pro mechanics that hang out there who are very knowledgeable and helpful.
 

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1993 400E
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7,361 Posts
Yes, he told me it was tested with mineral spirits and pressure tested. How much pressure?? At ambiant temp or operating temp?

MB has a known problem thats in the diagnostic directory with
these coolers.

__________________________________________




1994 E420

Mercedes Benz Technician since 1982
 

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1993 500E
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142 Posts
Discussion Starter · #10 ·
Thanks, everyone. We are going to try a new oil cooler to see if that solves the problem. If it works, I'll be relieved but still disappointed that my mechanic relied on a used oil cooler test and then tore down the engine to do another head gasket. Thanks for all of your help.
 

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1993 500E
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142 Posts
Discussion Starter · #11 ·
Ok, here is the deal being suggested by my mechanic. Right now I have a 2500.00 bill for the 90,000 mile maintenance and the work they've done so far to determine the cause of the oil, which included replacing the head gasket again. This is before the oil cooler install. They are quoting me another 1200 for the oil cooler and a new pipe by the oil cooler to replace the pipe that is partially siezed on mine and the labor to install. He is not guaranteeing that the oil problem is going to be solved by replacing the oil cooler as he is very confident the original oil cooler passed he pressure test. Another option he is giving me is to install a new to me used engine. He has one with approximately 37k miles and he will put it in for $1800. What would you do? I'm at $3700 if I go with a new oil cooler that doesn't guarantee the problem will be solved, or $5300 with a newer engine that will have a warranty. Or, I could just pay my bill of $2500.00 and walk away from the car as it will be pretty much worthless, unless someone wants a real nice 300SE with a suspect oil problem. It is silver with grey interior and in great shape...any value with the suspect motor? I think it is actually worth saving, but maybe you will tell me to run away. I'm thinking of going with the motor and at least have a chance to get some of my money back if I sold it.
 

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1993 400E
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7,361 Posts
First, why is he charging you for a head gasket that didn't
correct the problem? Did you tell him to replace it or did he
tell you that was the cause of the oil in the coolant?

14 months is out of warranty at most shops (12/12000).

But if he diagnosed the new problem as the head gasket again
then there's a problem. He can't charge you for a repair that
didn't fix your car.

More information from the time you dropped the car off until
he pulled the head.
 

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2000 C280, 2006 E350, 1993 400E, 2007 SLK55 AMG, 1994 S500, 2008 E320 Bluetec
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At this point, don't pour any money into the issue.
I think you need to have a chat with your mechanic about the head gasket repair that didn't solve the problem. You shouldn't pay a dime for the repairs he just made - as he didn't repair anything.

Don't get led down the path of replacing the engine - the car is not worth that cost.

Take a moment and think about what your mechanic has/hasn't done to fix the problem. If the problem is still there, he misdiagnosed. If your car is the only one in his shop at the moment, it's clear where this is going...
 

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SL55, 300SE, GL450, Daytona 955i
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10,293 Posts
Yeah, I agree with everyone, I hate it when some mechanics bite more than the can chew by accepting a job they are not 100% confident they can fix. Then later on realize they cannot fix the problem, so they try to overwhelm the customer with a huge bill for the "time" they spent "misdiagnosing"... to eventually make it look like the customer denied the service due to the cost, rather than the mechanic not knowing crap what they are doing.

Here is what I would do, step by step:

1-Make sure you have the written estimate of the job, this is simply the legal contract between you and the shop that, after filtering all of the fancy terms, implies: "john doe" mechanic shop (seller) will "stop the oil problem by replacing head gasket" (job/product) for about "$2500" (quote, any reasonable variation +-10-20% is acceptable)

2-Make sure your car is back in one piece at the time of implementing this strategy (this is important)

3-demand the access to your vehicle without any compensation "quote" simply because the shop "seller" failed to deliver the promised "product" defined as "stopping oil leak"

4-misdiagnosing is the sole responsibility of the shop, otherwise, I ll personally open up a dental office tomorrow morning, and start diagnosing people: "I ll pull this tooth out, it may get better, it may not, but you have to pay me for my time..."

5-if the paper you have are quoting you for "replacing head gasket at customer's request without mentioning diagnosis at the shop then pay them and learn your lesson.

6-if they shop denies you access to your vehicle, request the sheriff or any other appropriate authority to be involved

7-good luck...
 

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1993 500E
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142 Posts
Discussion Starter · #15 ·
First, why is he charging you for a head gasket that didn't
correct the problem? Did you tell him to replace it or did he
tell you that was the cause of the oil in the coolant?

14 months is out of warranty at most shops (12/12000).

But if he diagnosed the new problem as the head gasket again
then there's a problem. He can't charge you for a repair that
didn't fix your car.

More information from the time you dropped the car off until
he pulled the head.
He told me after looking it over that it had to be the head gasket,and he even showed me where there was a little external leaking around the cylinder head. Then he said he usually warrants for a year but, after that time, he has to charge. So, based on his recommendation, I said to go ahead and start replacing the head gasket. Once he got the head off, he had me come down to the shop and show me that he was stumped; the head gasket looked fine and he didn't see any evidence of head gasket failure. He then started to say that he didn't know what was going on, he had never seen this before, and said maybe there was something wrong in side the head(cracks, etc) that would cost $$$ to test. So, then he put it back together, flushed the system, and that's when he discovered that the problem was still there.

I do not have an estimate in writing when he started the job as I have known the guy for years and he has been great so far. Maybe my mistake on that part.
 

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SL55, 300SE, GL450, Daytona 955i
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well, if you know the guy enough not to get a written estimate, then you should be able to talk to him about the bill...

also, average head gasket job is anywhere between 750-1500 bucks, the head gasket itself is 80 bucks. the rest is labor.
 

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1993 500E
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142 Posts
Discussion Starter · #17 ·
Yes, I was quoted 1000.00 for the head gasket, the rest of the amount was for belt tensioner and pully, main belt, and 90k maintenance.
 

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SL55, 300SE, GL450, Daytona 955i
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what is the 90K maintenance that costs 1500 bucks? I am positive mercedes does not recommend a new engine at 90K

not to mention, all of the parts that you mentioned need to come off anyway to replace the head gasket... so the labor is essentially already included in the head job, and the parts are less than 200-300 bucks.

no offence bro, I am just talking like this to open up your eyes, but sounds like this guy took you for a ride...
 

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2000 C280, 2006 E350, 1993 400E, 2007 SLK55 AMG, 1994 S500, 2008 E320 Bluetec
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what is the 90K maintenance that costs 1500 bucks? I am positive mercedes does not recommend a new engine at 90K

not to mention, all of the parts that you mentioned need to come off anyway to replace the head gasket... so the labor is essentially already included in the head job, and the parts are less than 200-300 bucks.

no offence bro, I am just talking like this to open up your eyes, but sounds like this guy took you for a ride...
I concur. Talk your mechanic out of the head gasket work. Pay him for the other work done at a reasonable price. Never return. Head to the dealer and pay $125 shop rate for a diagnosis.
 

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Banned
1993 400E
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7,361 Posts
I agree with everyone. Misdianoses that you shoudn't pay for.

Offer him "his" cost on the parts at best.

Also the cooler is between $450 to $550. $1200 is high to replace.

__________________________________



1994 E420

Mercedes Benz Technician since 1982
 
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