2003 LS V8 - Cooling fan not running, rough idle

[corcanian]

Hi all, first post! - have perused these forums with great success for past solutions and am very grateful for the many detailed descriptions of repair topics. Alas, I have reached the breaking point of requesting for help as I've encountered a problem(s) that are sidelining this vehicle!

Current Situation: she is running rough, especially when cold. accelerator has limited pressure until the throttle body is tapped and then she will rev up, but still idles rough. Just replaced the radiator after finding a crack in the passenger side, after replacement I can asses that the fan is not running. Admittedly, I did not notice if the fan was not running properly before I replaced the radiator. But the fan will not run.

Followed the diagnostics on this post: http://www.lincolnvscadillac.com/forum/showthread.php?85693-2003-LS-V6-radiator-fan-doesn-t-work
Red/Yellow has power. Can not get the fan to run by applying the 12v jumper to the green/yellow wire on the small connector, on either the new fan or the old one. I may be hooking it up incorrectly. But with the A/C active, the fan is not running.
Any suggestions on what I could be missing??

Problem #2:
Rough Idle
Especially noticeable during cold starts (coming up soon in MN!) The engine runs very rough until warming up. Check engine lights indicated coil problems (discovered this is a notorious problem), recently replaced the coils and gaskets earlier this summer. ETC Fail Safe mode occurs often especially during wet snowfall.

Codes from last scan before the gasket/coil replacement: P0316 (misfire), P0307 (cyl 7), P0302 (cyl 2), P0358 (ignition coil H), P2106 (throttle actuator control), P0430 (cat efficiency). Current codes: C1996 (active yaw control), P1000 (on board diagnostics not complete)

Things I am looking at / thinking about replacing, but wanted input before going through the investment:
1) Electronic Throttle Body / Throttle Position Sensor
2) Cylinder Head Temp Sensor - possibly unrelated to the rough idle, but possible indicator for the fan problem.

Car will run out of the garage, rough, but due to our colder temps now, does not appear be in danger of overheating. Although the fact I can't get the fan to run keeps the fan in the garage. Any suggestions would be very welcome!

 

[jjcool00]

A. Did you replace all the spark plugs along with the coils? Did you use motorcraft parts? Likely since you have P0430 you have destroyed your cats with the misfire.

B. Hate to ask - but did you plug back in the fan? There is a plug that sits on the radiator for the cooling fan (2 of them I believe). When I changed out the radiator, I forgot to hook one of them up and this happened to me. If everything is connected, then the fan could be dead. Check the relays first.

 

[joegr]

...Current Situation: she is running rough, especially when cold. accelerator has limited pressure until the throttle body is tapped and then she will rev up, but still idles rough. ...

There were some manufacturing issues with some throttle bodies on the 2003 model (first year for electronic throttle control). It sounds like you may have one and may need to replace it. The "still idles rough" may be another problem.

...Just replaced the radiator after finding a crack in the passenger side, after replacement I can asses that the fan is not running. Admittedly, I did not notice if the fan was not running properly before I replaced the radiator. But the fan will not run.

Followed the diagnostics on this post: http://www.lincolnvscadillac.com/forum/showthread.php?85693-2003-LS-V6-radiator-fan-doesn-t-work
Red/Yellow has power. Can not get the fan to run by applying the 12v jumper to the green/yellow wire on the small connector, on either the new fan or the old one. I may be hooking it up incorrectly. But with the A/C active, the fan is not running.
Any suggestions on what I could be missing??...2) Cylinder Head Temp Sensor - possibly unrelated to the rough idle, but possible indicator for the fan problem. ...

The radiator probably cracked because the fan was not running. By "new fan" do you mean new OEM fan, or new used fan from a junkyard? It sounds like the "new" fan is probably bad too. Changing the CHT is not going to alter this.

...
Problem #2:
Rough Idle
Especially noticeable during cold starts (coming up soon in MN!) The engine runs very rough until warming up. Check engine lights indicated coil problems (discovered this is a notorious problem), recently replaced the coils and gaskets earlier this summer. ETC Fail Safe mode occurs often especially during wet snowfall.

Codes from last scan before the gasket/coil replacement: P0316 (misfire), P0307 (cyl 7), P0302 (cyl 2), P0358 (ignition coil H), P2106 (throttle actuator control), P0430 (cat efficiency). Current codes: C1996 (active yaw control), P1000 (on board diagnostics not complete)...

I really hope you replaced all the spark plugs at the same time and set their gaps to 1.0mm (no more, no less). Pre-gapped plugs are often set wrong. Bad coils damage plugs and damaged plugs kill new coils. I also hope you used Motorcraft coils. They are the least expensive in the long run. You almost certainly need new cats now because of not dealing with the bad coils soon enough. ETC failsafe is often caused by bad coils, but in you case, the throttle body may actually be bad.

 

[corcanian]

Thank you both for the descriptions! That gives me a new direction to check into.
In response to your observances:

1) Plugs: new plugs were not changed with the new coils, massive oversight it appears on my part. Will be pulling them out to replace and evaluate whether the old plugs could have damaged the new coils.
I don't believe the replacement coils were motorcraft: #IC27 DG509 DG515 DG529 00-06 Lincoln Ls V8 3.9L Ignition Coil 8PCS http://amzn.com/B0051E4AMY
With new spark plugs: as far as setting gaps 1.0mm: use a coin or blade gap to measure exactly?

2) Fan: Replacement fan was a Dorman 620-164 - hard to determine if this new fan is working, even though it is currently installed (and a bear to install) - any recommendations on how to "hot-wire" it to verify the fan works? One concern I have is that the plugs don't snap or click together like the old ones... same issue I have with the plug going into the throttle body motor (does not click in)

3) Throttle Body: due to manufacturing issues, any recommendations on where to source the appropriate one? I see the Ford replacement is around $500, aftermarket BBK "performance" unit is about half price, or can I get by with just a replacement throttle body motor?

 

[jjcool00]

1) Plugs: new plugs were not changed with the new coils, massive oversight it appears on my part. Will be pulling them out to replace and evaluate whether the old plugs could have damaged the new coils.

I don't believe the replacement coils were motorcraft: #IC27 DG509 DG515 DG529 00-06 Lincoln Ls V8 3.9L Ignition Coil 8PCS http://amzn.com/B0051E4AMY
With new spark plugs: as far as setting gaps 1.0mm: use a coin or blade gap to measure exactly?

You really need to change the coils and all of the plugs again, ASAP to Motorcraft. This is the classic case of someone using off brand coils and/or plugs and losing their cats. I'm not trying to pick on you but there's hundreds of posts on here of people using the cheaper options and arguing that they have no negative effect on the car. The problem lies within efficiency. Off brand coils and plugs or malfunctioning coils and plugs leave fuel unburned to drip into the cats which damages them, fairly quickly. Unfortunately, brand new cats will run you into the thousand. If the cats have failed, an option is aftermarket. Several threads on this with mixed reviews/success. I believe Walker, Magnaflow (I have these and have no issues) and Eastern are all brands that have had success. Universal or high flow cats are a no-go. Also, I believe the coin style gapper is probably safest.

2) Fan: Replacement fan was a Dorman 620-164 - hard to determine if this new fan is working, even though it is currently installed (and a bear to install) - any recommendations on how to "hot-wire" it to verify the fan works? One concern I have is that the plugs don't snap or click together like the old ones... same issue I have with the plug going into the throttle body motor (does not click in)

I believe some have had success with aftermarket fans. If the connector isn't connecting it may not be the right fan. Make sure yours is for a GEN II (2003-2006) and not a GEN I (1999-2002).

3) Throttle Body: due to manufacturing issues, any recommendations on where to source the appropriate one? I see the Ford replacement is around $500, aftermarket BBK "performance" unit is about half price, or can I get by with just a replacement throttle body motor?

I think a junk yard or used throttle body would be sufficient here. Not sure if anyone has attempted an after market throttle body.

 

[joegr]

I agree with using the coin type gap gauge, but do look up how to correctly bend the ground electrode to adjust the gap. If you try to force it open with the gauge, you will damage the center electrode.
I also agree with getting a used/junkyard throttle body. If you get a choice, get one from an 04 to 06.
Many have had bad luck with Dorman in general. Be aware that gen II used two different electric fan assemblies. You should have the one with two two-pin connectors. Later cars had one four-pin connector.