strange noises coming from front of OM617 engine.

[qualified-merc]

1984 300D turbo diesel. A few days back, strange rattling/knocking/nailing sounds started coming from the front of the engine. I am thinking of using a mechanic's stethoscope to listen to both the water pump and the vacuum pump. I'm also wondering if the injectors might be nailing. What is the best way to record the sounds of the engine and post to youtube?

[t walgamuth]

I'd check the vac pump first. If it comes apart the bearing balls fall into the cam chain and break it allowing the pistons to hit the open valves.

[JHZR2]

Just record a video with your phone to start.

Could be lots of things, vacuum pump is concerning. Does the cars vac work well?

[qualified-merc]

the door locks open and shut a little slow sometimes. Also, sometimes the trunk won't open after unlocking the driver's door and shutting the car off. The car has approx 250,00 miles on it. I know I have never changed out the vacuum pump during my time with it (about 25 years and counting now).


I have a new vacuum pump sitting on the shelf so I could go ahead and install it just to be on the safe side.

[Diesel911]

What kills some vacuum pumps is too much end play in the intermediate shaft that the timer gear mounts on.
See the picture in post 3.
Redesigned vacuum pump for the 617?

Another issue is bearing failure of the roller on the articulating arm of the vacuum pump.

[qualified-merc]

My question is this; will I be able to hear excessively loud mechanical sounds (rattling/knocking/clanking, etc.) if I place a mechanic's stethoscope on the vacuum pump while the engine is running?

[JHZR2]

Originally Posted by qualified-merc

My question is this; will I be able to hear excessively loud mechanical sounds (rattling/knocking/clanking, etc.) if I place a mechanic's stethoscope on the vacuum pump while the engine is running?

I’ve never had great experiences with a stethoscope. If you think you’ll record and post to YouTube I’d say it’s dubious.

If you put it right on some part and get a much more specific metallic noise I’d say that warrants a deeper look.

[automch]

There is only one sure way to know if it is the vacuum pump and that is to remove it and inspect all components. If it fails it could destroy your engine. They have been known to break the timing chains as mentioned earlier, which causes much destruction.


2nd possibility, with the engine off, check the fan clutch, is should be smooth and not grabbing in spots. Check lateral movement of the fan, if excessive carefully look to see if it is in the fan clutch or water pump shaft. Either are possible and if the water pump shaft is loose it will cause noise. If the fan clutch grabs or is rough it also will cause noise.



Good luck and don't wait too long before determining the cause.

[qualified-merc]

I am leaning towards going ahead and replacing the vacuum pump since I have a new genuine mercedes OE vacuum pump on the ready. A water pump won't kill the engine whereas a bad vacuum pump can. I'll then start looking for someone to remanufacture the old vacuum pump.

[qualified-merc]

I'm thinking of using Permatex Anaerobic Gasket Maker on the gasket for the vacuum pump prior to install. I'll also check and see if I have the Permatex Surface Prep spray on the ready beforehand.

[JHZR2]

Originally Posted by qualified-merc

I'm thinking of using Permatex Anaerobic Gasket Maker on the gasket for the vacuum pump prior to install. I'll also check and see if I have the Permatex Surface Prep spray on the ready beforehand.

I did one on a 603 this summer. The metal gasket was all that was needed. I didnt use Hylomar or Permatex aviation gasket maker which are my two go tos.

[qualified-merc]

OK, checked my supplies, the permatex surface pre aerosol can I purchased from NAPA won't spray properly. A special shout out to NAPA for wasting my time and money.

So, I'm thinking of two possible options to install the new vacuum pump. First, degrease the area around the vacuum pump then remove the old vacuum pump. Scrape as much of the old gasket off the engine side as possible.

1. Spray brake cleaner on the surfaces to prepare for the anaerobic gasket maker. Coat both sides of the vacuum pump gasket with permatex anerobic gasket maker then install the new vacuum pump.

https://www.permatex.com/products/gasketing/anaerobic-gasket-makers-sealants/permatex-anaerobic-gasket-maker-50-ml/

2. Clean both surfaces using brake cleaner. Then use Permatex spray-a gasket on both sides of the vacuum pump gasket then install the new vacuum pump.

https://www.permatex.com/products/gasketing/gasket-sealants/permatex-high-tack-spray-a-gasket-sealant-12-oz/

All input or ideas are appreciated!

[JHZR2]

Originally Posted by qualified-merc

OK, checked my supplies, the permatex surface pre aerosol can I purchased from NAPA won't spray properly. A special shout out to NAPA for wasting my time and money.

So, I'm thinking of two possible options to install the new vacuum pump. First, degrease the area around the vacuum pump then remove the old vacuum pump. Scrape as much of the old gasket off the engine side as possible.

1. Spray brake cleaner on the surfaces to prepare for the anaerobic gasket maker. Coat both sides of the vacuum pump gasket with permatex anerobic gasket maker then install the new vacuum pump.

https://www.permatex.com/products/gasketing/anaerobic-gasket-makers-sealants/permatex-anaerobic-gasket-maker-50-ml/

2. Clean both surfaces using brake cleaner. Then use Permatex spray-a gasket on both sides of the vacuum pump gasket then install the new vacuum pump.

https://www.permatex.com/products/gasketing/gasket-sealants/permatex-high-tack-spray-a-gasket-sealant-12-oz/

All input or ideas are appreciated!

What does the FSM say? I don’t think anything about some gasket dressing. Use the right gasket. FSM specifies thickness. I forget where I got the torque value - I think just generic for fasteners of this size.





Pretty sure I installed mine dry. The gasket was metal. Maybe one side had a permanent bead of silicone, iirc..?

Do you have a proper gasket????

[qualified-merc]

Yes, I have a new gasket. Funny enough I had been tearing the house apart looking for a magnetic drain plug I knew I had ordered. yesterday I opened the box containing the new vacuum pump and what do you know? Yep, not only was the vacuum pump in the box but there was the magnetic drain plug!

If it was a snake it would have bit me!

[qualified-merc]

Car was low on fuel so I filled up today with #2 diesel. I first added six ounces Amsoil diesel fuel additive then filled the tank. After I arrived home, I got out and carefully listened to the engine. Strangely, all the knocks, rattles, etc. are gone. She sounds like a 617 turbo diesel should sound.

Weird.