Ok heres a few things going on with my car, first ill give some details, feel free to let me know what you think about any of these. 01 z28 around 54,000 miles, bone stock. I run nothing but 93 or 91 gas in it and have the oil changed frequently with 5x30w val. synpower. The problems are....

1) a clear antifreeze smell when i pop my hood, but only after i have drove it.

2) after letting off of the throttle or holding 1/4 throttle it sounds like beads or something are rattling around in my intake/engine....then it quits once its back to idle

3) also at idle the engine seems to have picked up a ticking noise, ive listened to a few piston slap clips, but it doesnt sound quite as loud, but could possibly be the same. The only thing is the ticking quits as soon as you give it some gas and doesnt come back until it is at full idle, it does seem to vibrate the car, which is a new one also.

as you can see most of these issues come at idle. The car performs fine and i have no surging of any sort. All the gauges are fine and the car idles at around 600rpms. I was told maybe the water pump was the issue....any ideas?

 

your going to be pissed..... sounds like detonation to me... 01's have issues with detonation REALLY bad.. my 2001 Z28 started to detonate so bad on the dyno that i wasnt allowed a second pass... BUT it also put down 303 RWHP through an automatic BONE STOCK.... got good nubmers but something was very wrong in the engine... two other local people had the EXACT same problem on their stock 01's.... they had thrown about 2k at their cars trying to fix it.. finally gave up and sold their cars.... as did i..

so far they had it narrowed down to some bad knock sensors but the problem came back on theirs soon after it went away.. never did figure it out.. id be interested in what the answers from people on here are...

 

does your #2 problem get worse after an oil change?>
Because me car does something similar moreso when its cold but will still do it when warm, IT is loudest right after i change the oil

 

I do notice my #2 problem does seem to get quiter as the car gets warmer, but doesnt completely go away. But as far as getting louder after an oil change im not really sure i really couldnt tell that much of a difference. Detonation doesnt sound good, im just wondering if there is anyone who has expierenced any of these and was able to elimate their problem?

 

ttt for ya, im curious as to whats causing the horrid detonation.

 

Is the #2 problem listed detonation? Because it only happens to me when you get off the throttle and the RPM's are eitherat a constant or falling. And only from 1200 to about 1800...any opinions out there?

 

Try EFI Live to see what your ECU is saying that will tell all or change your intake seals AND VACUM LINES my o2 had loose vacum lines behind the intake and my car was brand new as far a the ticking i use 15 w 40 in the summer time and 5 w 30 in winter non synthetic castrol gtx all day!!!

 

pewterbird i dont think #2 is anything major myself, although it is a problem, since it only makes the noise when letting off the trottle or around 1500 rpms it probably is a hose or something simple like a pump or maybe even a filter. I have had a few people look at it and everyone has said it was either a pump, filter, or a hose nothing major.....I'll take it to a mechanic sometime soon to find out for sure.

As far as #3 issue, i started up my car just a few minutes ago and there wasnt any ticking at all. I let it warm up and reved it a few times and still no ticking very very wierd.

 

Yeah i was never too concerned with it being once i got on the throttle it stopped, still can be loud tho and i've never been ok with it. deffinately let me know what it is if you ever get it figured out

 

have you tried higher octane gas ( jus a gal of race gas)

 

I haven't, have always ran nothing but 93. I dont think it is pinging, it does it only when i get off throttle

 

i think i know whats going on with my #3 problem, its definatly not detonation.....i need to know how other peoples cars are setup to really know whats going on though......I'll post it in the external engine forum though........as far as the #2 problem im still working on that, let me know if you figure out anything.