BMW M5 Forum and M6 Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter #1
My 2000 M E39 threw an OBD code of P0128 "Coolant Thermostat (below regulating temp)". Cleared code came back. Before I could take it in, the car develops a roar at highway speeds during deceleration. Over 80 mile drive gets louder. Clutch became grabby when I stopped the car then tried to move it. It was towed to the dealer today.
Do I have a clutch problem? Could the coolant problem be related?
 

·
Registered
Joined
·
2,516 Posts
My 2000 M E39 threw an OBD code of P0128 "Coolant Thermostat (below regulating temp)". Cleared code came back. Before I could take it in, the car develops a roar at highway speeds during deceleration. Over 80 mile drive gets louder. Clutch became grabby when I stopped the car then tried to move it. It was towed to the dealer today.
Do I have a clutch problem? Could the coolant problem be related?
Not sure about your transmission clutch, but it sounds like your fan clutch is shot, which should be the loud noise you hear. Depending on mileage, I would also replace the fan, since these are known to "explode" and possibly throw a fan blade into the hood.

I would start with that and if you still have a cooling issue (too hot or too cold) then look into the temp sensors and/or thermostat.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #3
technician117,
Thanks for reply.
What other symptoms what come from bad fan or fan clutch?
My car has 150k miles.
 

·
Registered
Joined
·
2,516 Posts
technician117,
Thanks for reply.
What other symptoms what come from bad fan or fan clutch?
My car has 150k miles.
Over cooling and the loud whoosh noise from under the hood are the main symptoms. If you hear those, just bank on replacing the fan clutch and fan. No need to further diagnose it. At 150k miles, it's possible they've been done before, but no way to know for sure, and either way it doesn't matter. Do both as PM.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #5
T117,
So the problem is that the clutch is staying engaged too much and over cooling the radiator?
Fan is running, clutch is seized.
 

·
Registered
Joined
·
4,488 Posts
Well, technically if the t/s is working, the seized fan isn't overcooling the rad, it's overcooling the coolant in the engine block by blowing large amounts of air over it. That may have brought the t/s code in or your t/s may be going bad (sticking open).

It's very easy to check the fan by just spinning it by hand, but I believe the car is at the shop? They won't miss it if it is bad.

And the grabby clutch has nothing to do with the fan or t/s.
 

·
Registered
Joined
·
3,968 Posts
easy to check the fan clutch. start the car up(make sure engine is cold, ie first start of the day etc), take a newspaper and roll it up, take it and try and stop the fan from spinning with it. it should stop quite easily. i can reach in and grab the blade with my hand and stop mine easily. if it takes a lot to stop it or it wont stop then the clutch is toast. its a viscous clutch, the hotter the engine gets the more the clutch locks up and the faster it spins.
 
1 - 7 of 7 Posts
Top