wants to stall at cold startup

[ltoughguy]

I was wondering if anyone knows what is causing this problem. When cold only the x starts fine then goes on high idle about 1400 then goes back down to about 900 and wants to stall, it never actually does stall but catches itself and the rpm's go back up. it does this a couple of times then it's fine.Is this normal?
it's about 35 degrees here

also does anyone else get a sound like bearing rattle at initial cold startup for a brief second or so?
castrol syntech 5w-30 motorcraft filter




98 4.0 42,000 all stock

 

[section525]

Welcome to the world of 4.0 SOHC engines. All the problems you listed affect 90% of the members here with your same engine. Do a search for "sohc rough idle" or "sohc cold start" or "sohc POS" and prepare to be over-welmed with info and opinions. And welcome to the site! The search function can be your best friend!

 

[TPLYNCH]

Does it do this with the climate controls on "OFF"? Could be your IAC going bad. Also, do you have the OHV 4.0 or the SOHC 4.0? Helps if you specify which engine...

 

[ltoughguy]

this happens with the climate controls on. I have a sohc

 

[TPLYNCH]

If that's the case, then I'd say your IAC is bad. They seem to be failing a lot lately on the '98-'99's. Have you had the 00M12 repair work done on your timing chains and had the manifold O-rings work done as well?? The bad o-rings were a cause of idle problems with the SOHC as well. The rattle is probably the tensioners...

 

[ltoughguy]

I have no idea wheter the the upgrades were made I bought it about a year ago.How can I find out?I have an exened service plan ,should I just bring it in and tell them the symtems? Thanks

 

[TPLYNCH]

If the work was done, Ford should have it on their computer. FYI - If it's the IAC, that may not be covered by the Extended warranty (Extracare in my case). It wasn't for me.

 

[ltoughguy]

I called the dealer today and talked to find out whether or not the 00m12 upgrade was done and he said it was not. I exlained the symptoms to him and he said that is exactly what it sounds like and after installing them on previous vehicles it showed a major difference,he did not say for sure they would do the upgrade because the mechanic must acknowledge that the symptoms for the upgrade are present.since this only happens when cold I dropped off the x so they could check it in the morning. I'll let you know what they say. He also did say that it may be the iac which is not covered.

 

[ltoughguy]

Update .the dealer just called and confirmed it does need kit 00m12 and also that the iac is bad.I have the extra care warrenty and he said it was covered except the $50 deductible.

 

[TPLYNCH]

HMMM, Ford wouln't cover my IAC under the Extracare Warranty. Wanted to charge me $225!

 

[ltoughguy]

i did check my warranty and the iac is only covered in the premium care package oh well they may have made a mistake it cost me $54 for all the work.where is loctated anyway?and what does it look like?

 

[TPLYNCH]

It's on the drivers side of the throttlebody. Its a chrome cylinder looking thing with a little black cap sticking off of it. On your SOHC it's underneath the black "SOHC" shroud on the top of the engine.

 

[ltoughguy]

thanks guys. that kit they installed made a night and day difference I couldn't believe it,if it wasn't for the tip on the 00m12 kit, I would of thought there was nothing I could do.thanks again

 

[mikeh]

You must have found my thread. Glad you were covered. Mine was a major PITA since it was over the 72K and I decided to do the job myself.

The job made a world of difference to me also.

Check your oil level to make sure they didn't mess up your job for a while. And watch for burned oil smell from the engine compartment.

mikeh