Click/tick sound - is it injector pump - PeachParts Mercedes-Benz Forum

hsmith · #1 03-09-2010, 05:38 PM

Good Evening,

I just got back from Nashville a little while ago, its about a 160 round trip. My average rpm was around 2,500. I let her sit for about 15 minutes, and craked her back up. I heard the sound. From inside the car I thought maybe the rpm counter on the fly wheel might be loose. I got out and listen under the hood and I could not tell if the sound was coming from around the valve cover, or, the injector pump. For about three weeks I have had an oil leak where the IP attaches to the engine. I just kept a close check on the oil level and add it as need from a gallon of Shell Rotella 15W40 I keep in the trunk. I have thought about putting the gasket on the IP my self, but now with the click/tick sound, I guess I better find a good mechanic. The engine still runs great - just now the sound. Is it possible that the leak could have starved the IP of needed oil? Thanks for your help.

Hugh Sr
1984 190d (W201) 133,345

rrgrassi · #2 03-09-2010, 05:50 PM

My guess would be a hydraulic lifter having some leak back, or getting weak. How is the oil pressure? It could also be a slight injector nailing also. Does it vary with engine speed?

Diesel911 · #3 03-09-2010, 06:37 PM

I do not know how the componets are arranged on your Car. On other models of the same year the Vacuum Pump is driven near the same area as the IP and the V Pump could be a source of noise.

hsmith · #4 03-09-2010, 07:38 PM

Yes, the sound increases/decreases with the rpm's. The oil pressure remains normal.

Hugh Sr
1984 190d (W201)

NJ300sdl · #5 03-09-2010, 07:40 PM

My pump ticked for at least two years. Replaced the pump when three lines had low fuel output. Do not know if the tick was the problem.

charmalu · #6 03-09-2010, 10:57 PM

Check your timing chain. pull the valve cover and see if a link is loose.

I had a tick when first starting the engine when cold. went away after it was warm, noticed it in the R/F. Don`t remember now the time frame from when I first heard it until the chain decided to part company.

Charlie

rrgrassi · #7 03-10-2010, 12:33 AM

You can use a mechanic's stethascope to pin point the location. The vacuum pump is also a viable issue.

hsmith · #8 03-10-2010, 01:01 PM

This morning when I took my son to school the noise was louder than ever. I parked it after I got back. About fifteen minutes latter I cranked up, and the noise was gone - sounded normal. What a relief! If this happens again is there any kind of additive I can run through the engine to help the valves? I'm guessing it was a stuck valve. I had always used Shell Rotella 15W40. Thanks.

Hugh Sr
1984 190d (W201)

DieselClan · #9 03-10-2010, 02:16 PM

I had a similar noise last month in my 87 300D. I never thought nothing of it since the noise went away after the engine warmed up. I took it in to my mechanic for another issue when he discovered the noise too. He called me concerned (and positive) that the vacuum pump was the source of the noise and urged me not to drive it for fear of breaking the timing chain if it "broke apart" while driving. He took a tube (old hose type thing) and put it near the vac pump to let me hear the precise location of the ticking/clicking.

I ordered a new pump and had him put it on and it's been good (and quiet) since then. He showed me the old pump and turned out 3-4 of the bearings were missing out of it. You may want to have it checked out just for the sake of it.

Good luck!

P.S. I've been to Red Boiling Springs before and it's very beautiful out there. Especially during the spring!