Was driving my 240 last night, got to a light and my engine started sounding a little weird, almost like something was wrong with the exhaust. When the light changed, I started accelerating then heard a loud bang. Opened the hood and there was my fan on the side of the engine. The bolts connnecting the the fan clutch to the water pump sheared right off. At first I was thinking the water pump seized up but, I'm able to turn it freely by hand. Do you guys think it was in fact the water pump or, is it possible the fan clutch had something to do with it? I should probably also mention that my temperature compensation board seemed to act a bit flakey about a month ago. I bypassed it and my temp gauge would stay a little above the 9:00 position (about 9:30 - 10:00) but, never getting into red.

By some stroke of luck, the fan only bent a few fins on the radiator and didn't destroy anything else.

 

I'd change out the fan clutch AND the waterpump... fan clutch will usually lock in and turn with the pulley, without causing problems... just cheap insurance..

 

So do we assume that the waterpump pulley came off at the same time or did the clutch just separate? If the pulley came off then can you turn the waterpump flange? If the pulley and belt stayed on did you restart the engine?Did you overheat where water came out of the tank cap? How did you get the car home? What year is it?

 

Yes, the water pump pulley came off with the clutch and fan. The belts came off therefore, had no alternator. The was running on the battery and I was able to get it off the road. It is a 1988.

 

This time of year around Chicago and your temp gauge reads north of 9 o'clock? That's not right from the get go. Replace the water pump, it should come with new studs. Since you're there and have had cooling issues whether you know it or not I'd swap the fan clutch and thermostat too.

 

Just curious, has anyone seen failed motor mounts in a 240 series cause the fan to collide with something?

 

Interesting , so either the 4 studs sheared or the 4 lock nuts came off. Was there any work on the WP or fan in the last few months? Just sounds strange that this would happen. OK , oh can you still turn the WP by hand? Unless the WP froze or you have a lot of miles on it you may not need to change it unless you want to. It's not a big deal or a big cost. I would check everything out to make sure that the alternator and AC compressor and PS pump are all OK and then decide if I wanted to replace the WP. Good luck.

 

I bought the car in October and the only work the previous owner did (and he only owned for about a year) was a new timing belt and valve lash adjustment. There was no service records with the car, although, the water pump and radiator look newer. Mileage-wise, the odometer was broke when I bought it and it was broke when the previous owner bought so the actual mileage is unknown.

 

Yeah, I'm going to order a new water pump, fan (since 2 blades got cracked when it collided with the fan shroud) and clutch today from FCP Groton. I ordered a thermostat last week as I was planning on flushing the system and replacing next weekend anyways.

 

Your fan clutch can seize and the excess pressure from turning the fan (lost horse power) was transferred to those 4 small bolts.
Also a source of the funny sound.
Ed

 

Sounds good in theory...maybe it could happen that way but I've never seen it personally. Not saying it couldn't be what happened, just never seen it. Fred brings out a good point easily checked out. Check the motor and transmission mounts since they seem to always be overlooked. When you pull the water pump check for scoring on the impeller and block water outlet. Haven't seen it on a redblock but I have seen worn bearings in a water pump cause it to wobble and jam. Let us know what you find..

 

Hope it's not the motor mounts Swift, looks like a PITA to replace. I'll definately let you guys know what I find when I pull the water pump off this weekend. The clutch looks like it may possibly original so, Ed may be correct. I suppose another "shot in the dark" explaination is that bolts may have been fatigued/crappy quality?

 

It sounds like maybe the previous owner didn't tighten down the bolts for the pulley and it worked it's way until it was way loose.

 

That's kind of my thoughts too. They are not stop nuts and if not tightened enough they can easily back out. I still didn't hear if the studs broke or the nuts just came off?

 

All 4 studs are broke so, it wasn't from the bolts working their way off.

 

Ok...Replaced the water pump, fan clutch, fan, thermostat and flushed out the sytem today. When I pulled off the water pump, I didn't see any thing under the ordinary and the shaft was able to turn the impeller smoothly. After replacing everything, took her out for a 12 mile run and the entire time, the temp gauge was right in the middle in the 9:00 position which, before, it was a little higher.

So, I guess the culprit was either the fan clutch or the studs connecting the fan clutch failed. Thanks for all the input guys!

 

darkdelta,
both of my 240's mounts had sheared clean and the motor was probably bouncing around freely for a month or two before I replaced them. The fan never collided with anything, but the oil filter (1987) was getting crushed.