Water pump noise? Something else? - PeachParts Mercedes-Benz Forum

dbn1066 · #1 11-07-2007, 12:04 PM

Been searching with no luck...
Does a water pump make noise when it is going bad? I'm getting a metalic sort of whirling noise (almost like something is banging around) from the front of the engine (617.9??) Temp as been fluctuating at operating recently. Sometime running cool; sometimes around 100. ACC works fine heat, cool when and where it should. No change in engine performance. At first I thought a belt was squealing but eliminated that right away. The noise is not present at idle but starts around 1100rpm and gets louder as rpms increase; sometimes. Other times it is hard to even notice. Regardless, it makes me nervous/curious and I need help diagnosing it, please.

pawoSD · #2 11-07-2007, 12:20 PM

Yes, sounds very much like a dying water pump. My car sounded like a tin can was being banged around from the front of the car, after I replaced the water pump, no more sound. Check (or replace) the thermostat while you're in there too, it may be not working right.

dbn1066 · #3 11-07-2007, 05:07 PM

pretty certain its the pump. Can it be lubricated with a flush and fill with zerex or mb coolant, or should I just replace it and flush, fill, thermostat replace?

#4 11-07-2007, 07:40 PM

Too many times peepole blames the water pp, poor little bastard. Disconnect the belt and turn it b hand and see if you get a rough coarse feeling. If it spins nice, run the engine (briefly!!) see if the noise is there stiil, if it is obviously its on the other belt's components

Stevo · #5 11-07-2007, 08:32 PM

I've noticed that when the pump goes it usually starts leaking out of the "weep" hole. The alternator bearings are a possibility. The water pump is not serviceable, except by replacing the impeller, which is what you get as a "replacement pump". The actual pump stays right on the block, pretty cool design and cheap that way.

retx · #6 11-07-2007, 08:50 PM

Quote:

Originally Posted by Stevo

I've noticed that when the pump goes it usually starts leaking out of the "weep" hole. The alternator bearings are a possibility. The water pump is not serviceable, except by replacing the impeller, which is what you get as a "replacement pump". The actual pump stays right on the block, pretty cool design and cheap that way.

not trying to hijack the thread but, just in this past week, my radiator ran low twice, and one day i noticed water on the ground below the car. drove it for a little and then parked and climbed under it, looked like water was leaking where the pump is. but i cant tell because its coming from behind everything so i have no clear view. where is the weep hole? i need to get fix this asap as its not getting below freezing here. how hard will this be?

dieseldan44 · #7 11-08-2007, 10:30 AM

retx,

there are two weep holes. One on top of the pump and one on the bottom. The top one - look straight down at the pump and youll see it. Maybe 1/4" in diameter. Once you see it, the bottom one will be obvious.

water pump is 50 bucks + gasket. get 4 new fan bolts too while you are at it.

changing a water pump isnt too bad, it took me about 3 hours. hardest part is getting the fan off. you need a 10mm 6 point box end wrench, with the nose ground down so it can fit in there. PB blaster them beforehand.

go by the FSM article, Haynes has you removing the whole radiator which is totally, totally unnecessary.

EDIT:
http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=2730TGOG12810MJJQ0&year=1982&make=MB&model=300-DT-001&category=All&part=Water+Pump

You can see it at the top in the picture of the Laso brand pump. Its the hole right below one of the top bolt holes.

dd

dbn1066 · #8 11-08-2007, 04:54 PM

Finally had time for a closer look and the two belts running around the fan and alternator are very loose. They don't squeal and appear to still turn the alt well enough to charge. Could this be all or part of my problem? Could loose belts cause alt bearings to go? Effect the water pump? I will tighten them tonight and see what happens.

spark3542 · #9 11-08-2007, 05:18 PM

I had a similar noise that I thought might be water pump or turbo. My sound was only at idle and disappeared with application of throttle.

I got my can of WD-40 and shot it beneath the alternator pulley and it quieted right up. You may want to try that first. That one shot kept it quiet for about 5000 miles. I suppose I should go ahead and replace the alternator soon.

johntksr · #10 11-08-2007, 07:54 PM

Quote:

Originally Posted by retx

not trying to hijack the thread but, just in this past week, my radiator ran low twice, and one day i noticed water on the ground below the car. drove it for a little and then parked and climbed under it, looked like water was leaking where the pump is. but i cant tell because its coming from behind everything so i have no clear view. where is the weep hole? i need to get fix this asap as its not getting below freezing here. how hard will this be?

I had the same problem. It was the water pump leaking out of the weep hole. It wasn't very hard to replace. It cost me about $50 and an hour and 1/2 (from start to finish) to replace.

dbn1066 · #11 11-08-2007, 08:45 PM

ok, so forget I asked. Anyone aside from spark (thank you, BTW) care to actually give me some guidance? Some quick this is what to look for, etc. I only ask about things I have never dealt with and this is all I get: a hijacked thread? Try some WD40? Maybe this is a simple issue. I hope it is. guess I'll have to ask locally.

300SD81 · #12 11-08-2007, 09:07 PM

I had the same problem just a few days ago, and someone else mentioned replacing one then too.. Are all of our water pumps going bad at the same time?

Make sure you don't break the bolts holding the pump to the housing. I grabbed a new housing at the junkyard for $4, but a new one costs like $100... Turned a 2 hour job into a 2 day job... The housing gasket is also impossible to find.. I ended up buying blank gasket material and cutting my own. Autozone has a new pump for $32, quality seems pretty good.

johntksr · #13 11-08-2007, 10:38 PM

Quote:

Originally Posted by dbn1066

ok, so forget I asked. Anyone aside from spark (thank you, BTW) care to actually give me some guidance? Some quick this is what to look for, etc. I only ask about things I have never dealt with and this is all I get: a hijacked thread? Try some WD40? Maybe this is a simple issue. I hope it is. guess I'll have to ask locally.

I suggest you replace the water pump.

I used a 10mm wrench and needed to grind it down a little to fit. You can do a "water pump" search and find tons of threads on it.

steps

drain coolant

1: remove fan shroud and let it hang (optional)
2: remove fan clutch with fan still attached (Careful do not round the bolts)
3: with fan and clutch removed loosen the belts to the water pump by releasing tension on the altenator
4: unbolt the pulley that is on the pump

5: spray some PB onto the bolts and remove the water pump

6: clean gasket area and re install.....

7: reinstall all of the other stuff.. getting the pulley and belts on can be a pain since starting the bolts to the pulley on the water pump with the belts on it requires the same skill as opening and closing the fuse box

add coolant

buy a new pump.. not a remanufactured...

t walgamuth · #14 11-08-2007, 11:04 PM

Quote:

Originally Posted by dbn1066

Finally had time for a closer look and the two belts running around the fan and alternator are very loose. They don't squeal and appear to still turn the alt well enough to charge. Could this be all or part of my problem? Could loose belts cause alt bearings to go? Effect the water pump? I will tighten them tonight and see what happens.

A loose belt sometimes will sound like a bearing going bad. But a binding pump bearing could also make your belts wear and or break.

Tom W

dbn1066 · #15 11-08-2007, 11:27 PM

Thank you johntksr,
Forgive me folks, I didn't mean any disrespect with my earlier post. I'm stuck with the undesirable necessity to drive my (rust free)'82 300DT thru the upcoming PA winter and am a bit edgy as I cannot afford to even pay attention these days, let alone buy a steam cleaning, rust proofing, undercoating in addition to the mechanical maintenance issues screaming for my attentition before winter.

Update: I tightened up the belts via the tightener on the alt. mount and the noise originally mentioned is no longer present. However, I did not drive the car, just revved it thru 90C, fully hot. I will see what happens tomorrow during the daily child dropoff/commute 40 miles routine.
Thanks, All, for looking
Dan