Rough idle.

redscott33 · 23-11-2008, 11:10 PM

Sorry to bother you guys.
I have a 95 V8 LTD that I just got back from the spray shop for some minor repairs. I drove it out of the repairers and noticed its idle was a bit rough, but it was in there for a week so I thought it might just need a run. It was all downhill driving from there (Mundaring down to Swan View) so I did not notice the shocking idle. Once I got into Midland the idle problem reared its head and I had to stop in a gas station and have a look under the bonnet. There was what looked like a bit of smoke coming out from behind the engine and I was getting really worried. I limped it home and let it cool down. I started it up and noticed a hiss that I thought must have been a vac leak. I held a piece of hose to my ear with the other scouting around the engine and I found that most of the hiss was from under the upper inlet manifold. I ripped off the manifold today and found what looked like a dodgy vac hose and a possible leak from the upper inlet manifold gasket. The PCV valve was also out of its socket so I guessed that was where the smoke/vaporized oil was from. I tested the PCV and it worked fine, so I put some Ford Blue sealant on it and pushed it back in (sorry for the long winded explanation so far...... hang in there). I also put the same sealant on the manifold gasket. I put the top back on and turned the key expecting a nice idle but no, still a rough idle and the same hissing sound from under the manifold. I've been searching the net this evening for possible solutions and I've been scouring threads to see if anyone has had the same problem. The only thing I can think of doing now is to call work and take the day off, and then run it in to Ford in Midland to get a diagnostic check on it to see if any sensors are naffed. Maybe the hiss was there before and I did not notice it with the engine cover on. I have read in the threads that an idle sensor can make a bit of noise due to its vacuum so maybe that’s what I can hear. Maybe the fuel rail.
Any suggestions would be greatly appreciated.
Scott.

Biggav · 24-11-2008, 04:46 PM

hrmm cant help afaid not a v8 guru but one would think vac leak from somewhere for sure.

redscott33 · 24-11-2008, 11:36 PM

My thoughts exactly. I checked as many of the vac lines I could find and thought I had nailed them. I took it to Ford today to get a diagnic check on the sensors and they called to say the PCV valve was faulty. A bit strange seeing as how I had checked it the day before and it pushed air one way and blocked air going the other, but I took their word. They broke the gasket for the upper inlet manifold so I wont know the result until tomorrow when a new gasket comes in.
Heres hoping!
Thanks for the reasurance concerning the vacuum leak. I was pretty sure I was looking in the right place, but not quite 100%.
Regards,
Scott.

P5_LIMO · 18-05-2009, 09:11 AM

97 Fairlane V8 started this crap this morning. Mine started when switched from LPG to petrol. It let out a backfire which is unusual then now on petrol rough idle then stalls after 30 secs or so, smoke at rear of engine, loud hiss from under Inlet manifold. Checked the airbox, yep blew the springs every where so fixed that and checked all vacuum hoses Behind the engine - OK, def hiss from under the manifold. Did you ever find out what the problem was dude? I can only see 4 bolts that hold the manifold on, does that sound right and is it worth pulling that off to see whats going on or should I just wheel it in to Ford? Also no suprises with Midway Ford & the gasket - ex Swan View boy here, had my trials with them before.

:

P5_LIMO · 18-05-2009, 05:15 PM

: Pulled the manifold, blew a blanking plug off a pipe. Also learnt local Ford service manager doesn't have a clue bout these cars.....what a surprise. HE said oh no thats the brake booster line, yeah whatever. :yeees: Told him that was first thing I checked but was intact and that the brakes had usual feel, no loss of vacuum and leak was from different area of the engine bay anyway. 'Oh well it's probably your brake booster then. ( the one THEY replaced 8 months ago...) He then went on to do his 'wheel it in and we'll see what we can find'.. Got a rough estimate on cost, within reason of not knowing EXACTLY what it might be I asked.

: Oh 3 hours @ $50 an hour plus parts coz it's an old vehicle ya know? Probably needs new PCV, Gasket and hoses. So around $200 I asked, understanding some things ya just don't know without a perve but being on a budget I only wanted a rough idea. ' Nah your probably looking at between $400-$500' he says...yeah whatever.

: Turned out all parts were excellent except for the missing plug. These guys are incredible! :Up_to_som

Biggav · 18-05-2009, 06:40 PM

well then thats great only a minor issue if that.

redscott how'd you go with yours fix it all up?