idle bounces when cold engine

[derekpw]

'97 xlt sohc v6

When first starting with a cold engine, the idle goes up and down several times during the first minute. Kind of bounces. Any ideas on this? Thank you.
derek

 

[Alec]

What's the range that it goes up and down? Is it a very rapid change? Does it always smooth out after the engine is warm?

It's normal for the truck to idle hunt a bit when it's cold, just not excessively.

 

[Robert]

If the idle bouncing is excessive or if you have had it for a while and are just now seeing the idle acting differently then it is likely your lower intake manifold o-rings. Do a search for 00M12 to find out how Ford will pay to fix it.

 

[derekpw]

more info

To describe it a bit further, this only happens when cold,
the idle drops down to just above stalling, then creeps slowly back up to about 1500, then slowly back down, then back up, and on and on. This usually happens for less than a minute and then idles normally. I never see it happen on a warm or hot start up.

... and this only just started happening over the past week or so.

As far as the 00M12 recall, my truck now has 94k on it and I believe that is for those with 72k or less. So, I am outa luck.

 

[Jason_25]

Sounds alot like a vacuum leak to me as well. I would get it looked at by a reputable mechanic.

 

[derekpw]

o-rings

Is this related to the lower intake manifold o-rings?

Last time I had it at Ford Repair (88k, now at 93k), they said to get the chain tensioners and o-rings replaced. For several hundred dollars. That was to solve the tapping noise that I have had since purchasing it new. Since my mileage is above the recall mileage, they won't cover it.

 

[Jason_25]

Re: o-rings

Originally posted by derekpw
Is this related to the lower intake manifold o-rings?

Last time I had it at Ford Repair (88k, now at 93k), they said to get the chain tensioners and o-rings replaced. For several hundred dollars. That was to solve the tapping noise that I have had since purchasing it new. Since my mileage is above the recall mileage, they won't cover it.

Yes. As Robert mentioned above, it is likely your o-rings drawing unmetered air into the motor.

 

[dogfriend]

Are the o-rings you guys are talking about the seals where the injectors go into the intake? If so, is it a difficult job to just go ahead replace them yourself?

The reason I'm asking is that I had a 2.9L Ranger, and it wasn't that difficult to replace the injector o-rings. I don't know about the SOHC engine though.

I think he could save by doing the intake himself if he can't get Ford to pay for it. The tensioner repair sounds pretty difficult though.

 

[TPLYNCH]

Since this is a problem common to the early SOHC engines, try and get Ford to cover at least part of the cost. May mean *****ing (LOUDLY) to the dealer and to Ford Customer Service, but if you're persistant, you may get them to knock off at least half the cost. Others on here have done it, you can too!

You can also try cleaning the IAC to see if that helps the idle hunting as well...

 

[Robert]

Dogfriend - no the o-rings are for the o-rigns that seal the lower intake manifold to the top of the cylinder block. Both the upper and lower intake manifolds need to come off as well as everything else that is in the way. Ford allows about 3 hours for warranty work to do both the o-rings and the tensioners. A non-professional mechanic will probably double that time.

 

[dogfriend]

yeah, that sounds like at least a full days worth.....

never mind

Why did they use o-rings instead of a gasket, anyway? I hope they came up with better o-rings for the replacement.