Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-13-2015, 01:20 PM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
New water pump making whirring/roaring when cold - M103 '88 300SEL

We finally had to have a new water pump installed on my mothers 1988 300SEL (M103 engine).

We bought all of the parts and had a mechanic do the labor. I picked the car up, drove it home - the car was already warmed up, I guess from the mechanic running it, checking for leaks. He put on a new water pump, thermostat, belt and drained all of the old coolant and refilled with new Zerex G05 coolant.

Well the car set for a few days, as it isn't not used much. I was going to drive my mother to town and when I was warming it up, I noticed a roaring/whirring noise at certain rpms. We started to leave at it was making a really loud noise, started back home, but then it started to quit. We went on and it never made another sound. I kept a check on the gauge, it was running in the normal range and no leaks.

My question is - is there a break-in period for these? I don't think it should be making any noise. I was also thinking maybe there was air in the cooling system causing it. I don't know.

I am trying to do a little research before calling my mechanic. It was a pretty big job labor-wise and I hate to think it may be a bad NEW water pump and it has to come off again.

Thanks.
Reply With Quote
  #2  
Old 02-13-2015, 02:01 PM
Registered User
 
Join Date: Jan 2003
Location: Dallas
Posts: 776
No break-in for water pumps; it should be nice and quiet, even if there was some residual air in the system. Could it be the fan clutch? They will tend to howl a bit when first started cold, and then loosen up as the motor warms.
Also might check the tensioner pointer to be sure the belt is properly tight.

DG
Reply With Quote
  #3  
Old 02-13-2015, 02:54 PM
Senior Member
 
Join Date: Nov 2002
Posts: 681
guessing here but i'd say the shop set the belt tensioner too tight. good luck, chuck.
Reply With Quote
  #4  
Old 02-13-2015, 03:36 PM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
Quote:
Originally Posted by S-Class Guru View Post
No break-in for water pumps; it should be nice and quiet, even if there was some residual air in the system. Could it be the fan clutch? They will tend to howl a bit when first started cold, and then loosen up as the motor warms.
Also might check the tensioner pointer to be sure the belt is properly tight.

DG
Thanks!

Quote:
Originally Posted by porkface View Post
guessing here but i'd say the shop set the belt tensioner too tight. good luck, chuck.
Thanks!
Reply With Quote
  #5  
Old 02-14-2015, 12:52 AM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
I started the car and I do believe the sound is coming from the tensioner (or pulley) located above the alternator on the passenger side - that may just be a pulley and not the tensioner, because I do not see where adjustments can be made there. it looks like the tensioner may be below the water pump? I hope not, it would be terrible to have to remove all of this again. It was a pretty time consuming job. Our mechanic charged $200 labor.

It definitely was not making the noise before the mechanic installed the water pump. The belt does not seem too tight or too loose. Maybe it is a coincidence that the bearings have went out in it at the same time the belt was replaced?
Reply With Quote
  #6  
Old 02-14-2015, 06:21 AM
Registered User
 
Join Date: Jan 2005
Location: Columbus, OH
Posts: 627
Question

How old is the tensioner and the belt?
__________________
'89 260e (212K Mi.), '92 400e (208K Mi.), '92 400e (not a misprint) (146K Mi.), '95 C220, '81 240D--Sold
Reply With Quote
  #7  
Old 02-14-2015, 06:53 AM
Registered User
 
Join Date: Aug 2002
Location: Southeastern PA
Posts: 2,970
86560SEL, it may be a failing fan bearing bracket that is making the noise. I had that experience after a mechanic replaced the water pump in our 1991 300CE, due to the drive belt being over-tightened. If you are not a DIY'er replacing the fan bearing bracket requires stripping down the front of the engine ... quite expensive if you're paying a mechanic. If that's the problem buy a reconditioned fan bearing bracket from a MB dealer, rather than some cheap knock-off brand.

I would take the car back to the mechanic and get an explanation for the noise. There are many things that could be making the noise. In any case you would expect the noise existed when the mechanic finished replacing the water pump, and didn't suddenly appear right after you got your car back.
__________________
Fred Hoelzle
Reply With Quote
  #8  
Old 02-14-2015, 12:34 PM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
Quote:
Originally Posted by PARSHOOT1 View Post
How old is the tensioner and the belt?
Not sure about the tensioner, but the belt is brand new.

Quote:
Originally Posted by Ferdman View Post
86560SEL, it may be a failing fan bearing bracket that is making the noise. I had that experience after a mechanic replaced the water pump in our 1991 300CE, due to the drive belt being over-tightened. If you are not a DIY'er replacing the fan bearing bracket requires stripping down the front of the engine ... quite expensive if you're paying a mechanic. If that's the problem buy a reconditioned fan bearing bracket from a MB dealer, rather than some cheap knock-off brand.

I would take the car back to the mechanic and get an explanation for the noise. There are many things that could be making the noise. In any case you would expect the noise existed when the mechanic finished replacing the water pump, and didn't suddenly appear right after you got your car back.
Yeah, it didn't make a peep before that. We had the pump replaced because it was leaking water. We have already spent over $400 in getting the water pump replaced.

We will see. Thanks!

Last edited by 86560SEL; 02-14-2015 at 03:10 PM.
Reply With Quote
  #9  
Old 02-14-2015, 01:29 PM
Registered User
 
Join Date: Jan 2012
Posts: 6,241
Quote:
Originally Posted by Ferdman View Post

I would take the car back to the mechanic and get an explanation for the noise. There are many things that could be making the noise. In any case you would expect the noise existed when the mechanic finished replacing the water pump, and didn't suddenly appear right after you got your car back.

This is one of the reasons why I didn't install customer parts when I had a shop. The last person to touch the car is held liable for anything that fails later, even if they did nothing wrong.

Does this have an automatic or manual tensioner? A bearing starting to fail can be made louder my adding tension.

At this point we don't know what is making noise and can't reliably diagnose remotely.
Reply With Quote
  #10  
Old 02-14-2015, 03:09 PM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
Quote:
Originally Posted by 97 SL320 View Post
This is one of the reasons why I didn't install customer parts when I had a shop. The last person to touch the car is held liable for anything that fails later, even if they did nothing wrong.

Does this have an automatic or manual tensioner? A bearing starting to fail can be made louder my adding tension.

At this point we don't know what is making noise and can't reliably diagnose remotely.
My mechanic is going to look at it on Wednesday. He has a garage behind his house and he will sometimes get the parts, or he will let the customers bring them, as they are normally parts he would get anyway. I spoke to him about it at length and he said this car has an automatic tensioner and he did say that with the new belt installation that he added tension to it, but he said a little more, not much. It could be that, but it sounds to me like it is the pulley above the alternator, but I could be wrong.

Thanks.
Reply With Quote
  #11  
Old 02-14-2015, 07:46 PM
Senior Member
 
Join Date: Nov 2002
Posts: 681
an 88 103 engine has a manually-set tensioner. there's a screw, a nut, a guide and a pointer. not automatic. good luck, chuck.
Reply With Quote
  #12  
Old 02-15-2015, 10:19 AM
Registered User
 
Join Date: Aug 2002
Location: Southeastern PA
Posts: 2,970
86560SEL, as far as I know the tensioner on your vintage engine requires a manual adjustment, as porkface states. If somehow there is an automatic tensioner on your engine I am not sure how your mechanic could possibly add tension. That doesn't make any sense. Does your mechanic work exclusively on MB and BMW vehicles, or does he work on any brand vehicle?

When adjusting the manual tensioner it's necessary to loosen the center bolt on the tensioner 1/2 turn or so; otherwise, you will destroy the tensioner when turning the adjustment rod. If your mechanic was unaware of that step, he likely destroyed the tensioner and you will need a new one.
__________________
Fred Hoelzle
Reply With Quote
  #13  
Old 02-15-2015, 08:37 PM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
Quote:
Originally Posted by porkface View Post
an 88 103 engine has a manually-set tensioner. there's a screw, a nut, a guide and a pointer. not automatic. good luck, chuck.
How strange. My mechanic said it had an automatic tensioner. He just had it apart 4 days ago. Oh well.
Reply With Quote
  #14  
Old 02-15-2015, 08:41 PM
86560SEL's Avatar
Registered User
 
Join Date: Jan 2003
Location: east Tennessee (southeast USA)
Posts: 3,009
Quote:
Originally Posted by Ferdman View Post
86560SEL, as far as I know the tensioner on your vintage engine requires a manual adjustment, as porkface states. If somehow there is an automatic tensioner on your engine I am not sure how your mechanic could possibly add tension. That doesn't make any sense. Does your mechanic work exclusively on MB and BMW vehicles, or does he work on any brand vehicle?

When adjusting the manual tensioner it's necessary to loosen the center bolt on the tensioner 1/2 turn or so; otherwise, you will destroy the tensioner when turning the adjustment rod. If your mechanic was unaware of that step, he likely destroyed the tensioner and you will need a new one.
He usually works on all makes and models, but works on a lot of Mercedes and BMW's. He brought up the conversation to me when I was talking to him about the noise, he said your (my) car has an unusually seen set up with an automatic tensioner... he could be wrong though. I have no idea. Lord knows I know nothing about them. Well I hope he has no destroyed anything, especially if it requires tearing down the front of the engine again. I hope just once it is nothing too serious. Have not been able to catch a break here lately. We are already over $400 in a new water pump... I hate to spend another $400.

Thanks.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 02:03 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page