squealing water pump?

[delorean928]

Hi, after taking out VIN 3425 after much work including the famous water pump change. Everything is fine and the bleeding of the heating system went very well.
After around 3 to 4 hours engine running I began hearing a squealing noise (high frequency noise) when the engine warms up. It looks like it comes from the water pump. Does any body got a noisy water pump?
I bought my pump new on EBay from a guy who was writing that he had it too much but at reception I found the name of his company on the box and he is one of the DeLorean parts seller
So he probably sold the pump on eBay because of a defective batch or something like that The pump does'nt have a bolted pulley it is press fit.

[Patrick C]

Make sure the bolts on the w-pipe on the air intake are tight. That can make a squealing/whistling noise if air is escaping.

[David T]

Run the motor without the belt and see if the noise goes away. If it does you have bad bearings either in the water pump or the alternator. How tight did you make the belt?

[delorean928]

Make sure the bolts on the w-pipe on the air intake are tight. That can make a squealing/whistling noise if air is escaping.

Thank you for your answer. I'll checked the bolts again but they have been torqued to the right value with new gaskets. If they were not tight the noise would be because air is sipping in not escaping right?

[delorean928]

Run the motor without the belt and see if the noise goes away. If it does you have bad bearings either in the water pump or the alternator. How tight did you make the belt?

Thank you David for your help. I could try that but I'm sure it does'nt come from the alternator. I listened wel and it comes from the center. The belts are just tight enough not too slip I would say.

[DMCMW Dave]

Spray some brake cleaner etc at the joint where the W-pipe is attached to the engine and see if you can make the noise go away. I'll bet its an air leak as David mentioned.

[delorean928]

OK Thank's I'll check for these things tomorrow.
I'll let know the results. By the way we can hear the noise from the engine compartment even at a high speed like in 4 th gear.
Thank's again

[delorean928]

Sorry guys I did'nt have the time yet to work on my D.
I have a question for the brake cleaner test : if I have a leak at the intake joint and I spray break cleaner the engine will rev up won't it?

[delorean928]

OK I finally got the time to work on my suspicious and annoying noise. Apparently it begins only when the engine warms up. Once the noise there I removed both belt and it was still there so it's not the water pump, the alternator nor the ac.
I tried to spray starter help around the intake and throttle body and nothing wrong
It squeals to hell. Very loud. Maybe I should try the smoke machine again when the engine is hot?

[Kenny_Z]

Sounds like you're chasing the same noise I am. Do you have one of these? http://www.amazon.com/Lisle-52500-Me.../dp/B0002SQYSM

I may help you track the noise down to a certain part of the engine.