RoadWarrior222
12-20-2007, 04:00 PM
Hi folks,
The '88 voyager decided to give me a scare yesterday. It's the 3.0 V6. I was driving around during the day and started getting a knock at idle. When I got home I popped the hood for a listen, sounded like quite a hard knock and seemed to be coming from "inside" somewhere as opposed to under the valve covers or from the timing belt/waterpump area. I took the 710 cap off and didn't hear it any worse in there. The very lightest application of throttle made it disappear completely.
I had to go out again and was a little concerned, listened while I was driving it, no noise at all apart from at idle, then I was going up a hill in 3rd (top in the auto) at only 40kph and it seemed to do a bit of a dieselly knock then. Was straining my ears to hear it though.
Anyway decided it might be carbon and so screamed up a hill in 1st and did a couple of jackrabbit starts, also was doing that for diagnostic purposes, and haven't heard it again since.
The things that make me suspect carbon are...
Seems to have been running a bit rich lately, poor mpg, gassy smelling exhaust, "fruity" engine note. Could be O2 sensor, leaky injectors or a freaky vacuum leak I suspect I've got due to very very intermittent loss of power assistance on the brakes which I can't find.*
Since last weekend's snowstorm, with all of my driving being in the city, I've been stuck going reallll sllloww, either because of bad roads, or the last day or two, because of everyone who still thinks the roads are bad. I've barely got over 1500 rpm or 40kph.
And now I guess, 'coz I gave it a blast of throttle and the noise seems to have gone.
(*that thing is driving me crazy, I can drive around for hours and hours and not get it to happen, then other days, like about twice a month, it will happen within 20 mins of driving.)
Oil looks smells and feels okay, minor amount of mayo on the cap, no sign of it elsewhere under the valvecover, figure it was due to weather and short trip city driving. No bubbles in coolant etc.
Anyway, been meaning to look into the running rich problem, but haven't had time and weather for it. Also not sure quite where to start with it, don't think I've got any codes. CTS is only 3 or 4 years old I think.
So anything else I should check, could it be rod or bearing knock @ low oil pressure?? Anything to do to confirm it?? Anything to do to bandaid it for a few months?? (Got another motor for rebuild, will happen in spring hopefully)
thanks,
RW222
The '88 voyager decided to give me a scare yesterday. It's the 3.0 V6. I was driving around during the day and started getting a knock at idle. When I got home I popped the hood for a listen, sounded like quite a hard knock and seemed to be coming from "inside" somewhere as opposed to under the valve covers or from the timing belt/waterpump area. I took the 710 cap off and didn't hear it any worse in there. The very lightest application of throttle made it disappear completely.
I had to go out again and was a little concerned, listened while I was driving it, no noise at all apart from at idle, then I was going up a hill in 3rd (top in the auto) at only 40kph and it seemed to do a bit of a dieselly knock then. Was straining my ears to hear it though.
Anyway decided it might be carbon and so screamed up a hill in 1st and did a couple of jackrabbit starts, also was doing that for diagnostic purposes, and haven't heard it again since.
The things that make me suspect carbon are...
Seems to have been running a bit rich lately, poor mpg, gassy smelling exhaust, "fruity" engine note. Could be O2 sensor, leaky injectors or a freaky vacuum leak I suspect I've got due to very very intermittent loss of power assistance on the brakes which I can't find.*
Since last weekend's snowstorm, with all of my driving being in the city, I've been stuck going reallll sllloww, either because of bad roads, or the last day or two, because of everyone who still thinks the roads are bad. I've barely got over 1500 rpm or 40kph.
And now I guess, 'coz I gave it a blast of throttle and the noise seems to have gone.
(*that thing is driving me crazy, I can drive around for hours and hours and not get it to happen, then other days, like about twice a month, it will happen within 20 mins of driving.)
Oil looks smells and feels okay, minor amount of mayo on the cap, no sign of it elsewhere under the valvecover, figure it was due to weather and short trip city driving. No bubbles in coolant etc.
Anyway, been meaning to look into the running rich problem, but haven't had time and weather for it. Also not sure quite where to start with it, don't think I've got any codes. CTS is only 3 or 4 years old I think.
So anything else I should check, could it be rod or bearing knock @ low oil pressure?? Anything to do to confirm it?? Anything to do to bandaid it for a few months?? (Got another motor for rebuild, will happen in spring hopefully)
thanks,
RW222