Just bought a 1995 GMC xcab SLE 6.5TD Auto.


My wife swears it has an engine knock... She drives a 2004.5 Cummins... Engine was rebuilt 11 months ago by a reputable deisel shop..(saw Invoice of $7700.00) Engine does not seem to have a knock to me. It sounds like my brothers 1995 Dually... How can I check engine condition without spending any $$. No error codes stored.. (285,000km on truck... about 20,000km on engine)


Thanks Dan

Mechanics stethoscope should help you locate your noise.
Loose heater hose, or support bracket will do the same noise.

If you don't find a sound short on brackets or lines, loosen feed line injector by injector if no change no knock or they is "all a knockin" 6.5s have own unique sound different than Cummins.

Thanks for the input. I drove the truck to work today for the first time (about 70km). When I arrived the engine did not make the same sound as in my driveway. I believe it has an exhaust leak on the passenger side, and when it warms up it goes away... Exhaust Manifold? Turbo connection to manifold? Downpipe? I will be changing out the exhaust as it has some holes near the back when $$ allow. Are the 6.5 manifolds prone to cracks? I have a L56 engine.


Thanks Dan

not prone to cracks but the engine shop may not have torqued the manifold bolts down good enough rust makes it nearly impossible to get accurate torque reading while tightening.

To quiet an otherwise noisy engine, run a high cetane fuel, say 45-47 and use 16oz per tank Power Service. My '98 rattles like a garbage bin full of marbles on 40 cetane but gets smoothe as silk (well, as smooth as V8 diesel can get) when i fill up with 45 and add the juice.


Off topic a bit but i thought this may help with hearing engine-related issues. Good luck,

Fuel addative should be part of every fill-up. It runs better with it and keeps the fuel deposits down.
I had the cover off my IP a week back and was surprised at how clear it was, as oposed to the crud that's usually in the fuel filter bowl.

Again thanks for the input...


My brother has told me to plug the EGR with a screw and put the hose back on... He has a 95 dually 6.5 no EGR. What's the poop on this?


Dan

disabling the egr keeps soot from exhaust gases from clogging your "s" code intake manifold. i run an "f" upper and lower manifold. if you don't want to swap the whole thing you should do the mods listed on john kennedy's site under "tech tips". www.kennedydiesel.com Edited by: lupey6.5