So much for the "perfect" 300D ... more big trouble - PeachParts Mercedes-Benz Forum

Cazzzidy · #1 06-09-2004, 04:30 PM

A few weeks ago I replaced the thermostat on my 300D because it was running a little bit on the cool side and took forever warming up.

When I got the old thermostat out, I tested it in boiling water and saw no action. My instincts were right, it was stuck open.

But sure enough, after properly replacing the thermostat, the car started running too hot! Damn!

I gave up and brought it to my mechanic. He replaced the thermostat again ... car still runs a little hot.

He contacts me and says that the thermostat is not the problem. He thinks the radiator is a little gummed up, speculating I might have gotten some loose debris into a bad place when I did a coolant flush. I said, "Hmm, that doesn't make to much sense ... are you sure it isn't the water pump or head gasket?"

I didn't want to spend $550 on a new radiator and labor if it wasn't going to fix the problem.

He said if it isn't the radiator, it is the head. He said the head might have a small crack in it. He added he was almost positive it is the radiator and the head is fine.

I replied, "Well, if it might be the head, lets do a compression test before we replace the radiator."

He assures me that because the overheating is so minor the crack would be small and would probably not show up on a compression test. And since the motor ran so damn good, he knew it couldn't be the head gasket. He basically assured me their was no inexpensive test to see if the head was leaking coolant.

I gave him the go ahead to repalce the radiator.

...

And yeah, it still runs too hot.

He pulled the head off and found the head gasket to be broken between two cylinders, and into two coolant channels.

I think a compression test would have told us about the headgasket problem and saved me the money on the radiator, which I didn't need.

I do not want to have to pay all of the money for the radiator. I already have a $1300 bill, I do not think I should have to pay all the money for something that was obviously his mistake.

What do you guys think?

muybweno · #2 06-09-2004, 04:43 PM

dang that's pretty bad...you should ask that leathermag guy for more info since he know way too much about these cars and what they can do.

as for the 1300.00 bill....well....i dont know...i wouldn't pay it.. but then again IMHO it is seriously hard to find out what the heck is going on with overheating problems on 300D. I've probably spent about a good 600.00 in parts just tryin to figure it out... and guess what i havent yet.!!!

allen

MikeTangas · #3 06-09-2004, 05:01 PM

Not sure if the gizmo works on diesels or not, but there is a device that can sniff out hydrocarbons in coolant. Simply open the radiator cap and run the engine, if there is a head gasket leak chance are good you're getting exhaust into the coolant and the device will sniff it out.

JimSmith · #4 06-09-2004, 05:16 PM

Cazzzidy,

An earlier post on the subject, one of my favorites, noted the thermostat housing can be the problem. The housing can suffer from crevice corrosion under the thermostat housing support flange, leading to a perpetually available bypass port. This, when it gets big enough, can short circuit the usual flow of a partially opened thermostat, leading to an apparent loss of radiator efficiency since the flow path through the radiator is typically not a loss-less path. In the end, you do not get the full capacity of the radiator as the radiator is not taking the full flow of the system.

Another item could be your fan. The engine driven fan on a 300D, unlike a 240D seems to be controlled by a device that engages a clutch when the coolant reaches a certain temperature. If this item fails, you typically have problems at low speeds in warm weather, which are less severe at higher speeds or in cold weather.

In any case, I would be reluctant to let this search and destroy mission continue. Check the clutch thermal switch, and then the clutch itself. Then, if that is ok, check the thermostat housing, and if the support counterbore is pitted, try filling it with a material like JB Weld. Fill the pits and then smooth the surface so it is reasonably flat. Let us know if something works or doesn't. Good luck, Jim

engatwork · #5 06-09-2004, 05:18 PM

I'm of the persuasion that if I am going to remove/replace a head then a new radiator is a little "comfort" factor to protect the head but $550 sounds like alot to me. It is real easy to sink $2k into these engines.

Cazzzidy · #6 06-09-2004, 06:23 PM

Thanks for the suggestions, guys.

I am sorry if I didnt make myself clear -- we did find the problem. The headgasket was blown, causing the car to slowly over heat. Everything else checks out fine, including the water pump, housing, and internal tube to the head.

My question pertains to the ethics of asking for a discount on the radiator work, since it was absolutely not neccesary. If he would have tested the motor as I suggested repeatedly, the real problem would have been found right away and I would not have replaced the radiator. Basically, he did $550 worth of unneccesary work to my car.

Can I ask him to take out the new radiator and put the old one back in?

Can I ask for the radiator and labor at his cost?

What would you do in a situation like this?

WannaWagon · #7 06-09-2004, 06:39 PM

You won't want to hear this, but I think you should choke on the full cost. If you had insisted on the compression check and found out later that your mechanic didn't do it or misled you about the results, that would be one thing. But you didn't insist. In your own words, you suggested. You let him talk you out of it and then you OK'd the install of a new radiator. You made all the choices here, so you can't blame the mechanic. Just my opinion. Live and learn.

As someone else suggested, you could consider the new radiator insurance toward the head gasket job.

Cazzzidy · #8 06-09-2004, 07:09 PM

Yeah, I understand.

I like my mechanic a lot. He is a really nice guy. I would hate to be a pest ...

whunter · #9 06-09-2004, 07:09 PM

Quote:

Originally posted by Cazzzidy
I gave up and brought it to my mechanic. He replaced the thermostat again ... car still runs a little hot.

He contacts me and says that the thermostat is not the problem. He thinks the radiator is a little gummed up, speculating I might have gotten some loose debris into a bad place when I did a coolant flush. I said, "Hmm, that doesn't make to much sense ... are you sure it isn't the water pump or head gasket?"

I didn't want to spend $550 on a new radiator and labor if it wasn't going to fix the problem.

He said if it isn't the radiator, it is the head. He said the head might have a small crack in it. He added he was almost positive it is the radiator and the head is fine.
I replied, "Well, if it might be the head, lets do a compression test before we replace the radiator."
He assures me that because the overheating is so minor the crack would be small and would probably not show up on a compression test. And since the motor ran so damn good, he knew it couldn't be the head gasket.
He basically assured me their was no inexpensive test to see if the head was leaking coolant.

I gave him the go ahead to repalce the radiator.

And yeah, it still runs too hot.

He pulled the head off and found the head gasket to be broken between two cylinders, and into two coolant channels.

I think a compression test would have told us about the headgasket problem and saved me the money on the radiator, which I didn't need.
I do not want to have to pay all of the money for the radiator. I already have a $1300 bill, I do not think I should have to pay all the money for something that was obviously his mistake.
What do you guys think?

Drat:
The only point a court will look at is "I gave him the go ahead to repalce the radiator".
You are right; a compression or cylinder leak down test will find a bad head gasket.
You can try asking for a discount on the radiator; just do not hold your breath.
The only good coming out of this is no more overheating.
Have a great day.

unkl300d · #10 06-09-2004, 09:32 PM

Is your mechanic an indy Mercedes mech or a 'do any car' mech??

If the former, he should be knowlegeable enough to warrant the hourly rate.

Sometimes a hard-stiff top radiator hose only after constant running for over 35 miles can indicate a slight head gasket leak.
There may be other indicators like the sniffer test mentioned in prior response.

You, not a mechanic, suggested something valid. A comp. test.
How much is the test? How much is the labor on the rad swap?
What is low retail on the radiator?
Pay the difference and keep your old radiator and sell it for cheap.

take care.

Wasuchi · #11 06-09-2004, 09:56 PM

At the very least let him know that you are unhappy with the way things went and replacing a good radiator. He might give you a discount and he might not.

Cazzzidy · #12 06-09-2004, 10:00 PM

Yes, he is a Mercedes only mechanic who runs a large, clean, fairly popular shop. I like him because HE works on my car, not some 20 something chump who took a couple mechanic classes and got some on the job training. I would have thought he would WANT to do at least a little bit of real diagnostics.

It can't hurt to at least talk to him about it.

I would be happy paying "at cost" for the radiator. Mabye 30-40 an hour and his price for the rad.

LaughingGravy · #13 06-09-2004, 10:07 PM

Without a long story involved...
Your mechanic sounds like my former mechanic. Nice guy, doing his job the best he knows how, not trying to rook you, but doesn't know these cars inside and out. Maybe take other cars to him, but for your M-B, find an Indy who specializes in M-B, particularly our tried and true diesels. Pay your guy what you owe him, but at least ask for any discount he can offer since it ended up not being the radiator as you suggested. Maybe he'll do something. Maybe not. If you like him for work on other cars, stay on his good side by saying it was worth a try and pay what he says. Then, try not to take your M-B back there. Just don't tell him that.

Here's my suggestion..keep a pile of business cards in your car, or print up small flyers..
Anytime you see an old M-B parked, go out of your way to get to it. Leave a note admiring their car,saying you have an old diesel MB and are looking for a good mechanic who knows these well, that you would appreciate a name and phone number or address.

Worked for me. I ended up with a fellow also suggested on this forum. I couldn't be happier.

muybweno · #14 06-25-2004, 06:57 PM

speaking of mechanics....are there any her in Colorado?? as what any M-B diesel owner would say " I've got a serious problems, can you help me?"

SHARK1007 · #15 06-25-2004, 08:35 PM

FYI: I just installed new radiator today in my 82 SD. The wholesale cost on the non aluminum radiator that was recommended was $138.00.

Sit down with the mechanic and tell him your concerns, let him know up front that you will abide by his decision as to what is fair. Tell him you have appreciated all he has done, but you aren't excited about the added expense that could have been possibly avoided. Put the bee on him to tell you how he would expect to be treated if he were you.

If he gives you a reduction, he has proven his integrity and you should keep him. If he doesn't, attack him immediately or just don't use him again, whatever meets your needs.