: Stupid Taurus.....



DopeStar 156
12-26-08, 10:16 PM
I'm having issues with my '99 Taurus with the DOHC 3.0 V6 and was wondering if someone might be able to help me out a little.....

My "Service Engine Soon" light is on and the idle speed keeps jumping about 400 RPMs. It sounds like there's a vacuum leak coming from behind the engine but I can't get to anything to even check. Not much of an expert on FWD engines and not too good with Fords, does anyone have any tips for this one? I replaced the IAC motor last year and had a vacuum leak fixed for a similar, but more severe problem......

dirt_cheap_fleetwood
12-26-08, 11:47 PM
Take it to Autozone or Advanced Auto Parts and have them scan the computer and tell you what the code is for. That will help pinpoint the problem.

DopeStar 156
12-27-08, 01:30 AM
Actually I work for AutoZone's commercial department and I did the scan myself. Banks 1 and 2 are giving lean codes......

Sorry thought I posted that......

Red_October_7000
12-27-08, 02:39 AM
Check coolant system for air pockets, in some cars air in the cooling system can cause a bouncing idle. It can cause serious damage if left unchecked. That said, my familiarity with FWD Ford motors is functionally zilch.

Night Wolf
12-27-08, 07:15 AM
I'm having issues with my '99 Taurus with the DOHC 3.0 V6 and was wondering if someone might be able to help me out a little.....

My "Service Engine Soon" light is on and the idle speed keeps jumping about 400 RPMs. It sounds like there's a vacuum leak coming from behind the engine but I can't get to anything to even check. Not much of an expert on FWD engines and not too good with Fords, does anyone have any tips for this one? I replaced the IAC motor last year and had a vacuum leak fixed for a similar, but more severe problem......

Heh, a guy at work has a '96 Taurus and said his check engine light is on, idles bounces and it sounds like there is a vac leak from the firewall side of the engine too...

Thats about all I know tho :( Not sure what it could be.

LS1Mike
12-27-08, 12:17 PM
Does it do it when the car is hot and cold, just hot or just cold.
You know either open loop or closed loop?
FWD or RWD shouldn't matter to much they all have the same systems.

Ranger
12-27-08, 01:43 PM
Sure sounds like you have a vacuum leak somewhere. Spray some Brakleen around the manifold gasket and listen for an RPM increase.

FrankT
12-27-08, 04:56 PM
Check for a vacuum leak as mentioned, here's where to check:

The upper and lower intake gaskets
The PCV hose under the throttle body and at both valve covers
The brake booster hose and at the throttle body.
If you don't find a vacuum at those points, replace the PCV valve its a little tough to get to, its under the upper intake and a wire harness by the throttle body. One more thing it could be is a TP sensor. Go to autozone and pull codes and post.

LS1Mike
12-27-08, 07:38 PM
He has banks 1 and 2 lean.
That is why I asked it does it all the time or just in closed loop.
Could be a Vacuum leak but OBDII Generally won't give a lean code on a Vacuum leak.

FrankT
12-27-08, 08:52 PM
P0171 - System Too Lean (Bank 1)The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code is set when the adaptive fuel tables reach a rich calibrated limit.Fuel System:
Contaminated fuel injectors
Low fuel pressure or running out of fuel (fuel pump, filter, fuel supply line restrictions)
Vapor recovery system (VMV)
Induction System:
MAF contamination
Air leaks between the MAF and throttle body
Vacuum leaks
PCV system concern
Improperly seated engine oil dipstick
EGR System:
Leaking gasket
Stuck EGR valve
Leaking diaphragm or EVR
Base Engine:
Exhaust leaks before or near the HO2S
Secondary air concern
Powertrain Control System:
PCM concernP0174 - System Too Lean (Bank 2)Same as DTC P0171, but Bank 2.See Possible Causes for DTC P0171

I had one of these cars give me the run around for an erratic idles, it didn't have the lean code but it had a P1506 engine idle high. It turned out that the Pcv valve was opening too much due to an internal failure of the valve. Its worth a new pcv valve at high mileage on these cars less than 10.00 for new one.

DopeStar 156
12-30-08, 12:15 AM
I took the car in for an oil change and the shop had told me it was my MAF sensor. Changed it out, reset the Service light and it came back on. I guess I'm gonna have to go through that list one by one.....

Ugh....

FrankT
12-30-08, 08:32 AM
That MAF Sensor must have set you back at least $250.00 bucks, I would take it back, demand my money back for his mis-diagnosis. Don't let them touch your ride again. I really think you have a vacuum leak at the PCV hose that located under the throttle body or a bad PCV valve. Here's a quick trick. Start the car and remove the pcv hose at the front valve cover if you have full manifold vacuum at the hose, replace the pcv valve. If no vacuum then look for a collasphing or leaking vacuum hose.



It sounds like there's a vacuum leak coming from behind the engine
It could be, but all of these engines sound like they have a vacuum leak because of the design of the upper intake plenum.

Good luck, let us know if you need anymore help!

DopeStar 156
12-31-08, 02:01 AM
The MAF sensor was actually under $100 but I'm gonna go ahead and do what I can to try and get this all settled. I'll be sure to report back.....