Service Engine Soon...

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Sep 29, 2003 | 05:54 AM

wdsmithjr

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From: Chesapeake, Va

Service Engine Soon...

I have a 1999 f150 4.2L, my Service Engine Soon light has come on. The oil level and radiator levels are fine and it runs good. However, I get no heat inside, the blower fan is working fine. I checked the heater hoses and both were equally hot, my old ford and jeep the return line was always cooler then the supply line, is this supposed to be true for this truck also? My wife also said (buts she's not 100% sure) that she thought one day the temperature switch was hard to turn but is fine now. Would any of this trip the light or should I be looking elsewhere? Or am I just going to have to bite the bullet and take it to the dealer to have the codes read?

Sep 29, 2003 | 06:15 PM

aldridgec

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From: Wake Forest, NC

There are ways to get the codes without the dealer, but it will involve a scanner. The heater controls don't normally trip the light, so it is a problem elsewhere. You need to find out the code as there are too many to speculate.

Sep 29, 2003 | 06:18 PM

AegisSailor

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From: White Sands, NM

Drive to the nearest Autozone and they will read it for free. Write down the number they give you and post it on here, someone will fill you in on what it means.

Sep 30, 2003 | 04:51 AM

wdsmithjr

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From: Chesapeake, Va

I'll pickup the truck tonight and hit up AZ and post the codes they give me here Wed. morning. Thanks for your time.

Sep 30, 2003 | 06:17 AM

bgdgtch

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From: CO

Sounds like the temp switch could be jammed to the cold side. I would take the panel off and look at the back side of the switch to see if you can tell if the switch has gone bad. As far as the check engine light goes... you need the codes read. More than likely what Roger said, an unrelated problem.

Oct 1, 2003 | 05:19 AM

wdsmithjr

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From: Chesapeake, Va

Ok, hopefully I've remembered the right number, P0455 said it was a vacuum leak. With it sitting idle it had a pattern where it'd run smooth then rough then back to smooth. When it was rough I could hear what sounded like air blowing but it was muffled. Hard to describe. Also I played with the temp switch inside, the first time I turned it (from cold to hot) after the truck was running it bound up about the time the pointer was straight up, then it felt like it was dragging the rest of the way to hot, then smooth as glass and then started blowing hot air. Is'nt the switch electrical and everythings operated by vacuum? Possible the two are related?