Engine knocking noise

Issues pertaining to the TGB/C30X series engine and driveline issues
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kc4mne
Posts: 28
Joined: Mon Nov 21, 2005 2:19 pm
Location: Ft Lauderdale, FL

Engine knocking noise

Post by kc4mne »

Hello

I have a knocking noise in my engine.

Kind of like a rod bearing knock, exept when the engine gets HOT it almost goes away. It is more pronounced at idle and just above idle.

Since it gets quiter when engine heats up I don't think it is a rod bearing, my guess is that a rod bearing would get louder as the engine oil gets thinner due to heat.

Valve lash was adjusted to tight .45MM with the engine cold.

Could this be a worn out piston pin. Wierd for such a low kilometer engine.

Any clues? Should I worry?

Manny
lindenengineering
Posts: 715
Joined: Sat Apr 17, 2004 6:14 pm
Location: Golden Colorado USA
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Post by lindenengineering »

Manny
This symptom sounds like one I saw recently.

The problem we had was gummed up piston wrist pin causing skirt slap against the bore.
I suggest you do the chemical treatment first.
On a fresh oil change pour in a can of MOA available from your parts store. Repeat this over several changes it should eradicate the gum build up due to an engine left unused for a considerable period like that Volvo you have.
You also might want to do the gas treatment whilst you are at it by adding a can of BG44K, following the instructions. Don't use substitutes this is the stuff we use unless you want to get the engine Motorvac'd.

We use this technique on negelected Landrovers that often suffer from sticking valves and cause a random miss fire to be thrown into the works throwing on the mil lamp.
Dennis
kc4mne
Posts: 28
Joined: Mon Nov 21, 2005 2:19 pm
Location: Ft Lauderdale, FL

Post by kc4mne »

:( tried the MOA in the oil with no change in noise. How can I figure out which cylinder is knocking. No difference in knock tone at idle by pulling one wire at a time at the distributor.

any ideas

manny
M Wehrman
United States of America
Posts: 847
Joined: Thu Apr 15, 2004 9:46 pm
Location: Gilbert, Az.

Post by M Wehrman »

Not knowing about the volvo plant and it's possible "quirks",on most any other engine if a problem was in a rod brng,wrist pin,piston,it would definately change with a wire pulled,I think this would be a good sign, how about timing chain ? Low KM's should discount wear but what about a sticking tensioner as it could "free"up when warm. I'm drawing from experiences with other OHC motors,G.M.,Toyota,nissan,etc. My only Swedish experiences were with Saabs and an almost date with an exchange student in high school! :D TTFN,mark
Stock means no imagination!


Volvo TGB1317, .95% Morphed!



68 Haffy
Lightningpinz
Posts: 218
Joined: Mon Apr 19, 2004 7:32 pm
Location: Lakewood, Co

Post by Lightningpinz »

Have you used a mechanics stethiscope? This will help narrow down what part of the engine the noise is coming from. front, back, top, bottom, driver side or passenger side. That in itself will help point to the problem.

Sean at work stole one of the last of the Viet's estate c303's. His had a "trerrible" knocking. After he adjusted the valves on his new c303 he asked for help and with the stethiscope it was the distributer. A little oil in the dizzy and it went away for a week. Like the advertisement for ask.com in this country "without tools we are just animals with pants".
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