Busted radiator and fan, chance of engine damage?

[JHZR2]

Literally writing this from the side of the interstate waiting on AAA.

Was driving my 1991 MB 350SD, 65-70 mph, heard a clang, felt like it bumped on my tire. Watched gauges and mirror, saw something was kicked up. Looked at gauges and saw temperatures rising.

Turned on heat as fast as I could, looking for a safe stopping place, pulled over and shut off. Not sure how far I went in that time, a few tenths?

Pulled over to find that the fan had come off, blade hit radiator, total coolant loss.

Ugh.

I think the fan just fell down in there, but the right pulley, and smacked the radiator.

Stupid Chinese fan clutch. Bought it based upon photos on rock auto. Stupid me. Thought it was reboxed OEM. Stupid me. Installed it anyway. Still stupid me. Realized it didn’t cycle (there’s a thread on that). Stupid again. Kept the car consistently cool. Beautiful cold AC.

But somehow the bolt backed out. It’s not broken. Notionally the water pump is ok.

I can’t spin the bearing in the fan clutch though. I think it seized and caused the bolt to back out.

The good-ish news is that I never saw the needle go over 100C. I shut it down before then. I pulled load relatively quickly when checking things, and was at highway speed so I guess there was some ram air.

I waited about 20 mins, turned the key to on, the gauge temperature reading is below 80C. I cranked the engine and it started perfect and idled beautifully and as usual for the 5-10s I let it.

Mercedes has an “upgraded” 11 fin plastic fan and matching OE clutch. So I’ll get that. No idea about radiators… project will probably be on hold until sept.

Questions:

1) what’s the chance that I destroyed my engine losing all coolant at highway speed? It is an iron/aluminum engine unfortunately.

2) what’s the chance that my head gasket was weakened or affected by this even though the engine runs?

3) if I need to maneuver the car where it’s parked, is this an issue to run for maybe 10-15s at a time if I let it cool in between?

4) If I want to wait for cooler weather to replace the radiator and fan, should I be concerned about corrosion in the system? Obviously all coolant is gone more or less. It had JD Cool Gard in it.

5) can I get this radiator repaired? Or the plastic top transferred to another?

Im most bummed because I doubt I’ll find a nice OE radiator like this again. Ugh.

Thanks for any insights….

 

[JeffKeryk]

If oil temp didn't get too high and you never lost oil pressure you should be fine.
Good luck!

 

[ripcord]

You didn't overheat, so you're fine. 100c is nothing to worry about in the slightest and would not affect anything. Having it sit without coolant in it for a few months isn't going to hurt anything, either.

Consider using some blue locktite when you put it back together next time.

 

[RooflessVW]

You're fine, I say.

New rad, new fan, new clutch. Send it.

 

[RooflessVW]

You may check out a Duralast clutch. (I know)

The one I got for the Trooper was the HD option and was made in the USA. Cheap too.

 

[Chris142]

You would have to drive it several minutes to damage the engine . Sounds like it was just a few seconds...it's fine

 

[JHZR2]

If oil temp didn't get too high and you never lost oil pressure you should be fine.
Good luck!

Oil circuits weren’t affected. Car ran just got warm.

You didn't overheat, so you're fine. 100c is nothing to worry about in the slightest and would not affect anything. Having it sit without coolant in it for a few months isn't going to hurt anything, either.

Consider using some blue locktite when you put it back together next time.

I know from servicing these cars that the temperature sensor is in the head at a spot that tends to get an air bubble. So it probably was relatively cool. However, can’t be too sure.

You may check out a Duralast clutch. (I know)

The one I got for the Trooper was the HD option and was made in the USA. Cheap too.

Since I need a fan now too I’ll probably just go with the OE 11 blade setup in full. Or steal the one from my 1991 300d.

 

[JHZR2]

You would have to drive it several minutes to damage the engine . Sounds like it was just a few seconds...it's fine

Yes certainly wasn’t several minutes. Could have been a mile from initial clang to realizing what happened, but I recall it wasn’t at 100 when I was at a stop on the side of the road. Iron/Aluminum engines worry me all the same.

 

[Passport1]

I doubt you suffered any damage to anything but a dent in your wallet. I also had a 126 chassis Merc. Mine was an '89 300se. Gas in line six cylinder. Great car, very comfortable. Only time it overheated was when the plastic top radiator hose outlet broke in my driveway. That car was more considerate to me than most people.

I remember the 350SD had some kind of issues with the block. Did yours have that?

 

[Dave Hess]

Dang, sorry to hear the bad news. Hopefully no damage to engine.

 

[JHZR2]

I remember the 350SD had some kind of issues with the block. Did yours have that?

The 350 was a 3.0 bored out to 3.5L. So the hg was smaller in some places. They were prone to hg failures (both of mine have had it), and bending rods if coolant or oil got into cylinder #1.

I know mine had a HG service because it’s in the records.

 

[Trav]

I have seen them a lot hotter than that from people just trying to fill them with a funnel. Replace the broken parts and move on.

 

[walterjay]

I once lost complete coolant and really steamed up the engine. No problems thereafter. You are likely good to go.

 

[cptbarkey]

Agree with others, the engine is 99.9% likely just fine. You shut it off well within the danger zone which I would wager would be past 3-5 minutes. Mostly the pride was damaged and a high stress situation. Sorry to hear about the failure. I am sure it will live another day after being fixed up better than before.

Back when I was 21 or 22 I ran a car for a good 25 minutes hot, I was young and dumb. It clearly blew the head gaskets but was still able to get it repaired. Swore ever since to never let that happen again after self educating. Also saw plenty of folks during cash for clunkers doing stupid stuff (not using the prescribed water/sand mix) and engines would last a very long time, sometimes 45 minutes or longer until they would finally die.

 

[supton]

Sorry to hear this. I think you're fine, but, regardless, not much choice but to run it, until the next problem. What are you to do, proactively tear it down to the bearings, just in case the head gasket might have been compromised? Seems far wiser to put back together, take it for an easy run, then push it progressively harder, then assess if anything may have been damaged.

I lost coolant in the head on my TDI (small hose line let go) and drove it 20+ miles home (coolant temp sensor was in the block and registering a very slowly rising temperature for the rest of the drive home). Seemed to suffer no ill effects (but I get it, completely different engine family).

 

[TheLastWord]

Some 2500 hp dragsters have no cooling system. You'll be fine.

Not a parallel comparison but you get the idea.

 

[Soft Cars]

That radiator tank is metal correct? There's good way to repair that, but it takes about 48 hours to do it.

 

[dumkid]

If you ran it for less than 5 minutes it's 99% chance fine

 

[JHZR2]

That radiator tank is metal correct? There's good way to repair that, but it takes about 48 hours to do it.

Plastic top and bottom. If I could get them attached to the right size core that would be good. Doubt people do that for a reasonable price…

 

[eljefino]

Your engine is fine. As the radiator drained your water pump was still sucking up what was in the bottom and pushing it through the engine with positive pressure.

My biggest concern is #4, but then junkyard engines sit around for years with air in the coolant passages and they do fine when pressed back into service. Maybe you could get a radiator in there in the next couple weeks, fill with coolant, then fiddle with the fan clutch when you get more time?