The engine in my 1998 e300d shut down today while driving home. I pulled to the side of the road and saw my temp gauge was sitting at 120. I turned on the heat, popped the hood and took a look. Belt was fine, no signs of a fluid leak, and the electric fans were running. I let it cool for a while and cautiously started it back up. The temp gauge was at about 90 and I drove the last 2 miles home, never exceeding 110 deg.

A more careful look revealed interference between the fan and the plastic fan shroud. Evidently the shroud had warped quite a bit and a fan blade became wedged behind it, stopping the fan and (I believe) the water pump.

The shroud warped at the 9 o'clock position (while facing the vehicle, as if you could see through the radiator). The plastic in this area should lay flat against the radiator, but instead it raised away, causing the interference.

I trimmed away the offending portion of the shroud using a knife to score the plastic and tin snips to finish it off. The shroud went back into position easily, and I made sure all the tabs were properly seated in their mating pocket in the radiator.

So...

Do you think I did any engine damage?

Fan clutch damage?

Should I do any preventative stuff, like oil change, coolant change?

Thanks,
Paul

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1998 E300D 1-tank Elsbett Veggie system
1986 190D 2-tank Veggie system -Sold

Check the lower radiator core support. Aggressive parking (hitting barriers with the part under the bumper) can push this back, causing the fan to run too close to the radiator and shroud.

In addition to steep driveway approaches.......

Check the front belly pan for scars; you can use a pry bar and/or hunk of 2 x 4 to lever it forward where it is supposed to be.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

When I got my '96, the front-most belly pan was missing and the lower radiator support was pushed back more than an inch. although less than yours apparently was. My mechanic and I discovered this problem when we attempted to install the new belly pan section. Fortunately, we were able to lever the radiator support back into place with no harm done.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Thanks for your replies. I took a quick look at the position of the radiator relative to the fan, and the space between the 2 is much less at the bottom than the top. I bought the car with belly pan scars and a major scuff on the front right bumper, so this matches your diagnosis well. Next time I'm underneath it I'll see if it can be re-aligned.

Now that I think of it, I remember someone put slots in the bolt holes on the belly pan! I wish VW had slotted the belly pan on my wife's Passat, that would make it almost possible to get it back on!

Should I be concerned about damage due to overheating? Is the car programmed to shut down the engine at high temps?

thanks for all your help!

Paul

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1998 E300D 1-tank Elsbett Veggie system
1986 190D 2-tank Veggie system -Sold

Hi

When my 98 overheated due to a broken water pump impellor it went into limp home mode. It didnt shut down altogether. It freaked me out because i thought it was gonna sieze cos it lost power.
2 years and 60000 miles later all is fine.
I think you should be ok.

McCool300TD

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1988 190E Sold
1996 C230K Sport Sold
His: 98 E300TD Estate, 7 seater, Avantgarde, Silver, Black cloth, parameter steering, dipping rvm, folding mirrors, rain sensing wipers, pentagon tints, 17" Elegance wheels. 298K
Hers: 93 300TD, 7 seater, Grey MB Tex pearl blue metallic, 15" 8 hole alloys, OTG, Cruise, not much else 220K

You almost certainly did not stop the water pump from turning. That would have made a racket so terrible that I am sure you would not have kept driving. Check your electric auxiliary fan. It should have been able to keep the engine temperature down.

The AC will shut down at 125C. I don't think it will ever just shut the engine down on you due to temperature.

I would go along with those who say that you did no damage. If damage was done, it won't be made any worse by continuing to drive it. Just make sure the coolant and oil are at the proper levels and in good condition.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

OK, now I think I might have another problem as well. I previously thought that the fan clutch also engaged the water pump, but after reading Matt L's post I realized that this would be silly, since the water pump is an essential part of the cooling system and shouldn't ever be disengaged. Even if the fan is stopped, the water pump should still turn.

This leads to my new concern. Immediately after getting the car home after the overheating incident, I felt the radiator and it was COLD. This says that no fluid was passing through radiator, suggesting a malfunctioning water pump, or perhaps a stuck-closed thermostat.

How do water pumps fail? There is no sign of fluid leakage in the area. Is it possible for the impeller to come loose from the shaft?

Can thermostats stick closed? A new thermostat was installed in the spring (because the car ran cool) and has run at 80degrees since, reaching 90 only sitting in traffic in the hottest weather.

anything else?


thanks for your help!

Paul

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1998 E300D 1-tank Elsbett Veggie system
1986 190D 2-tank Veggie system -Sold

I suspect a better test would be to feel the upper and lower rad hoses or shoot them with an IR thermo.

The rad fins are designed to disapate heat and when the car is moving is very efficient at that task.

I'd monitor your temp gauge at the dash or using teh CCU as the dash gauge may not show temps above 95C until you reach ~110C, at which time the gauge will jump forward to that temp.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Thanks Terry, I just came in from a test drive and the car is still overheating. The lower radiator hose is cold and the upper is hot. What do you think?

thanks!
Paul

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1998 E300D 1-tank Elsbett Veggie system
1986 190D 2-tank Veggie system -Sold

Prob the thermo. What temp was it?

Check it using teh CCU screen. Press and hold REST for 5 secs, use right AUTO button for 5 secs and toggle to screen 6. It may read in F or C.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

The impeller can break. I can envision a situation where the stopped fan put pressure on the shaft, causing the impeller to hit the housing.

That doesn't sound very likely, but a non-functioning pump or stuck thermostat seems to be the case.

Unplug the auxiliary water pump, put the heater controls on HI and see if you get any heat. If so, you have pump action but a closed thermostat. If no heat, you have no pump action.

The ECT sensor reads 109 deg after a short drive in my neighborhood. (the dash gauge is well above 80, so both must read in Celsius).

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1998 E300D 1-tank Elsbett Veggie system
1986 190D 2-tank Veggie system -Sold

At those temps both the aux fans and fan clutch should be engaged at low speed with the AC on. Check that they are both working. Aux fans on, and clutch locked up (howls with throttle, and can't stop fan using a rolled up newspaper).

I like Matts test.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)