sluggish Q goin south
sluggish Q goin south
this post is premature as i've not done any diagnostic work yet. but i can't help myself. as i posted earlier "sluggish Q", i had poor performance and some vibration at 2500 rpm . over the last couple of weeks (150 miles?) it started making what sounded like a hydraulic lifter problem. after a ten mile 70 mph run down the interstate the car quit while sitting at the traffic light at the end of the exit ramp . it restarted but made alot of "clatter" i had to drive a hundred yards to get out of the intersection . now when you start it the clatter is ugly but it quickly settles down to a single knocking sound. as earlier posted the car had recent (less than 7,000 miles) head gasket/value job/ timing chains & guides . it has been troublesome since the job was completed returning for injectors,fuel pump blah, blah..the mechanic said he had trouble "getting the HVA's pumped up" i briefly looked at the service manual , but couldn't tell if the valve cover will come off w/o removing pletum. obviously there are many things to check before that but from what i've seen posted here i don't want anything to do do with removing that.i'm really hoping it's rocker arm related. the car has 129,000 and the body and interior are in amazing condition. but just in case some of you are bored you can speculate how bad off i am. thanks
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greg_atlanta
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Jeff Williams
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2000 Infiniti I30t
2004 Infiniti M45
71, 72, 73, 82 & 2000 Corvettes - Contact:
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Again it is amazing that people resist taking measurements of things. I am a nut for test equipment: gauges, exotic tools, etc.
This week's prizes from ebay: A Keller zero to 200 bar [2800 psi]digital handheld pressure gauge, a 2300F Omega electronic thermometer, a Dwyer 80" WC manometer................ $1400 worth for $150 including freight.
Now I can finally measure the restriction all the way from the air horn to the MAF at WOT. Something that can stand the shock wave [pressure change] of a closed throttle vs WOT.
It's like pulling teeth to get someone to test their oil pressure....much less compression or leakdown, or transmission line flow rate.
This week's prizes from ebay: A Keller zero to 200 bar [2800 psi]digital handheld pressure gauge, a 2300F Omega electronic thermometer, a Dwyer 80" WC manometer................ $1400 worth for $150 including freight.
Now I can finally measure the restriction all the way from the air horn to the MAF at WOT. Something that can stand the shock wave [pressure change] of a closed throttle vs WOT.
It's like pulling teeth to get someone to test their oil pressure....much less compression or leakdown, or transmission line flow rate.
We got pounded pretty bad by the hurricane ,just got power back on saterday, so the Q has had to take a back seat. i don't want to run the car so it will have to be towed to one of a couple of friends of mines shop that have the proper eguipment. my biggest time issue is the warranty for the orginal head gasket ,valve job, timing chains and guides is almost up. If the top end is lunched, i'll probabably take my chances with him again before i spend thousands on it . if it looks like it's going to be trouble again i'll have to reassess if i want to make it right. the last owner "older driver" used synthetic oil for the last hundred thousand miles untill all the problems after the work started and he decided to throw in the towel b/c he didn't trust it anymore . he used regular oil on the last oil change a few months ago. the oil idiot light has never come on . the bad fuel injectors that came out looked like they had been physically damaged rather than going bad (tips broken) so at this point i'can't vouch for any of his work. it's a shame b/c it's really in above average condition otherwise. the shop is in raleigh so i'm trying to make sure it's something that will be under warranty before i tow it 200 miles to the %*&%#@ shop. maybe i'll be lucky when i get the v. cover off ,but it doesn't sound good. the bearing is always a possibility since it did have a head gasket failure ,i just don't know if it would take 6500 miles to fail?? thanks guys
brought "Slug Q" to a friends shop for computer scan and compression check. i called back and they first said they thought it might be a pulley gone bad on the front of the engine but then called back convinced that it's a rod knock and that there is no need to do compression check. these guys are not Q guys so I'm not really convinced. so it will go for another opinion . the rod is a definate possibility . but there is a pulley (resistance ) sqeaky sound as you bring up the rpms that was not there before the car stalled on me at idle and all the noise started. couple of questions b/c i may total the car and cut my losses, if it is a rod what are my options other than a swap? they used a scope to look in the oil filler opening an said it looked gook (oil flow , & rockers i guess) is there a harmonic balancer that could cause anything like this (or part of the noise and vibration) i'm just reaching for things to check and i guess i still need to do a comp. check. is there any way to confirm the rod short of disassembly? and lastly what to do with the car if i thrown in the towel.
I'm not sure what they were looking for through the oil filter port. Maybe metal shavings? Definitely can't see the lifters through there. The balancer is a lump of mass fixed to the crankshaft. It could be out of balance possibly, but I wouldn't think it would be enough to be very noticeable. Besides checking the oil pressure for poor bearing oil clearances, you can disconnect the injector on the suspected cylinder to see if the knocking gets quieter.