|
|
|
|
|
#1
09-15-2012, 11:09 PM
|
|||
|
|||
|
Croaking/burping noise when rotating engine
Hi guys
I have an engine I pulled from a 77 300D, when rotating it over by hand I get a noise that sounds a lot like a rapid "pop pop pop pop" but so fast it's actually like a croak or groan or burping noise. The valve cover is off and it appears to be coming from the front of the engine, possibly up from the timing chain area. What the hell is it? Is this from compression/blowby? It doesn't seem to be from just one cylinder's compression, it happens for a second or two then stops then happens again regardless of who's turn it is for squeeze. Vacuum pump? Something broken? Normal? Thanks Steve 
|
|
#2
09-15-2012, 11:39 PM
|
||||
|
||||
|
Thats the sound of the air compressing/getting past valve/rings when moving it slowly. Normal. More noticeable on a diesel than a gas engine.
__________________
-diesel is not just a fuel, its a way of life-  '15 GLK250 Bluetec 118k - mine - (OC-123,800) '17 Metris(VITO!) - 37k - wifes (OC-41k) '09 Sprinter 3500 Winnebago View - 62k (OC - 67k) '13 ML350 Bluetec - 95k - dad's (OC-98k) '01 SL500 - 103k(km) - dad's (OC-110,000km) '16 E400 4matic Sedan - 148k - Brothers (OC-155k)
|
|
#3
09-16-2012, 08:00 AM
|
|||
|
|||
|
It's probably the sound of the vacuum pump doing its job. It's operated by an eccentric driven by the timing chain so either 2 or 4 compressions (pops) per revolution.
__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.” ― Brian P. Cleary, You Oughta Know By Now
|
|
#4
09-16-2012, 04:03 PM
|
||||
|
||||
|
A regular 'belching' or croaking noise is from the vac-pump, quite noticable without cam-box fitted or the pumps pipework is off, while turning motor...
Quite normal,--its the action of the valves in the pump you hear as its passing air-- most types of vac-pump on 617 and 60x discharge the pumped air into the crank-case, so thats why you hear it more with the lid off.... there are one or two types that dont discharge the air to crank-case--they have an additional pipe to air-cleaner,--they croak just the same..... --Nothing to worry about.....
__________________
http://i190.photobucket.com/albums/z...0TDnoplate.jpg Alastair AKA H.C.II South Wales, U.K. based member W123, 1985 300TD Wagon, 256K, -Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.  W114, 1975 280E Custard Yellow, -Great above decks needs chassis welding--Really will do it this year....
|
 |
| Bookmarks |
|
|
Linear Mode
