Just thought I would throw this out there, its not the usual GM wrist pin slap' never had it before. Emission light came on and wife took it to the dealer. they played around with plug and coils #3,#5 as per scan codes.. This was Friday so I can't go in and see them till the 1st of the week. Question, engine has audible tick below 2000 rpm. Goes away after 2000 rpm. Would a bad plug wire cause this ? Sounds like a vacuum line off but there isn't. coils are good. Work order comments about difficulty removing plugs. any ideas ?? Wasn't on a warm engine just cold start today. Thanks guys.
4.8, 5.3, 6L engines are common for exhaust manifold to cyl head bolts breaking, quite possibly the source of the noise. check the very front or very rear bolts, see if the bolt heads are missing.
Intake manifold leak permitted coolant to internally enter my engine ruining it completely in my 99 Sub. Eventially it sounded like a ticking in right side valve cover turning to a low end knock accompanied by Check Engine light. Nothing a good rebuild couldn't fix. Rod bearings were shot, crank reduced to a paper weight. Sorry to be severe but if coolant is missing I'd find the source.
-- Edited by 73SC on Sunday 25th of April 2010 12:12:10 PM
Good idea to get the oil tested for coolant I guess. They are good guys but I don't want to see the boys at Atchinsons with this one. My transmission guy has the test kit, $50/test.
In the older 4.8V, 5.3T and 6.0U litre engines, the intake does not contain coolant like 73SC's 5.7R engine does. I have done a ton of these as well for that condition! (The same can be said of the 4.3X-W and the 5.0M engines with this same style of gasket)
But I have done a couple sets of head gaskets for these due to coolant entering the base and it has cured it. The customers did notice loss of coolant in the meantime... Has your coolant been disappearing??
I was going to reply this morning on this fact but I was late for work and my typing skills suck!!! I am a 2 fingered louie on the keyboard and it can take me forever to type a larger paragraph...........
-- Edited by 67Poncho on Monday 26th of April 2010 07:52:29 PM
LOL----weeelllll, I don't know about that..... Experienced would be a better word! I just want to clarify that there are coolant pipes going to the front of these intakes, but it is just for the warming of the throttle body that is bolted to the front of the intake...........
