engine noise on cold start up
 

I have noticed two 'new' noises in the 84 300 TD, when the weather is aroud zero degrees out.

The first is what appears to be a ticking sound comming from the vacume pump, or the little box above the vacume pump, that is attached to the fuel control rods.... any Idea?

And the second one sounds like noisy tappets, or followers, again only on a really cold day and it goes away after the engine has warmed up. I just adjusted the valves 2000 miles ago... or is it a oil flow problem?

Jason

the second noise is probably the valvetrain making noise waiting for the oil pressure to come up. I'm more familiar with the Cummins engines, but they do the same thing in extreme cold. Synthetic oil seems to help this problem a LOT for me. I've only had my 83 300DT a few days now, but I notice it behaves similarly on the coldest mornings when the oil is thick.

My vacuum pump is noisey too when its under 20 degrees outside and the engine is cold. I have an 84 300D. I have had brand new cars make noise in those temps too so its not limited to our older cars.

I neglected to state that the vacume pump noise is durring the glow plug cycle, but it does not seem to be the glow plug relay... as that is what I thought it was at first.. could a glow plug click/tick?

Time to isolate that noise. I use either a length of hard plastic tubing or part of an old rake handle, preferably hickory or ash.

JD, I had ticking sounds from that area on 2 occasions, both serious. Neither of the ticking sounds near the vacum pump/timing chain cover area were related to the engine temperature...they ticked the same sound level all of the time. I have the old style vacum pump, but the cam follower stuff with the tiny bearings may be the same style as your 84 330 TD, I dunno??.

The first occasion was the bearings on the vacum pump were failing. I found out about this when they suddenly disintegrated and fell into the oil pan while driving. A new pump and that ticking sound was gone.

The second occasion was from the timing chain beginning to disintegrate because the circlip link came off at some point while driving and also fell into the oilpan. Luckily I replaced the timing chain in time so I had no engine damage. The second ticking sound is also gone.

FWIW, I would recommend checking the condition of the vacum pump and then carefully examine the condition of the timing chain. Either one failing could spell disaster.




1979 300D with old-style vacum pump.

I have discovered that the ticking noise will not repeat itself if the glow plugs are cycled twice... May be it is the glow plug relay sticking??
Sorry to be so slow to respond, have not been near a computer since last week.
J

yeah
 

it pretty much cant be valve noise. the lifters are mechanical so dont respond to oil pressure.

hope you figured it out. if the glow plug relay is sticking it will toast your battery charge in no time. prb not good for the gps either.

tom w

good point about the mechanical lifters!!

Do you think the glow plug relay would be sticking on? I guess I was thinking that the relay was having trouble switching on in cold weather, therefore making a clicking noise... but then I dont know anything about relays.

i dont know
 

about a glow relay.

the glow plug timer may be a relay too. it can fail and buzz or hum. if it does it will be quite noticable.

tom w

Thanks for the information. I will go looking about the car some more tomorow.
Jason