'03 LS8 won't rev

Gus_Mahn

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Our '03 LS8 has a newer issue. Sometimes after a cold start. It won't rev. My wife thought the trans was having issues (it was replaced 6 months ago along with the ECM), as it wouldn't move. After a few seconds, it did/does. I started playing with it and figured out it won't rev as you give it throttle in park or neutral. Once it does start to rev, it's extremely slow. It probably takes 2.3-3 seconds to get to the 3000 rpm P/N rev limiter. The car drives fine otherwise and seems to be completely normal in drive. Any thoughts? Could the ETC actually be failing or dirty/gummy?
 
Our '03 LS8 has a newer issue. Sometimes after a cold start. It won't rev. My wife thought the trans was having issues (it was replaced 6 months ago along with the ECM), as it wouldn't move. After a few seconds, it did/does. I started playing with it and figured out it won't rev as you give it throttle in park or neutral. Once it does start to rev, it's extremely slow. It probably takes 2.3-3 seconds to get to the 3000 rpm P/N rev limiter. The car drives fine otherwise and seems to be completely normal in drive. Any thoughts? Could the ETC actually be failing or dirty/gummy?

Its something to do with the drive by wire throttle set up. It's pretty common on Mercedes, It's a peddle position sensor or something along those lines
 
2nd gen LS's throttle by wire system revs REALLY slow, thats normal. but not reving at all is an issue.
 
Have you tried cleaning the MAF sensor?
Thanks. No, but I'll do it tomorrow. The sensor is only old about 2 years old. I lived with a pinging '97 F-150 for about 2 years until it set a check engine light 2 months ago. Guess what the issue was? Air meter was dirty. Cheap and easy fix. I hope the Lincoln is the same, though I doubt it.
 
I started playing with it and figured out it won't rev as you give it throttle in park or neutral. Once it does start to rev, it's extremely slow. It probably takes 2.3-3 seconds to get to the 3000 rpm P/N rev limiter.

Normal operation on 2003 and up. Designed this way. Move on.
 
Normal operation on 2003 and up. Designed this way. Move on.
I've had the car 5 years. I am very familiar with the car, I understand there is a rev limiter, and it revs lazy in park and neutral even in perfect working condition. This is something more.

Did you read my first post, or do you suffer from poor reading comprehension? Is it normal for your car not to move when you press on the gas pedal in gear/reverse?
 
What you are trying to say is sometimes, when it is cold, it is revving at a slower rate than what you normally expect the car to do under these conditions. You understand that it has a cold engine RPM limiter, and know how the car should act when cold, and it is not operating in a normal fashion when cold.

Would you say that it acts like a carbed vehicle does when the choke doesn't work, where it's a challenge to get it to start and run? If so, I would take a guess that a cooling sensor is not operating correctly, and is telling the computer that the engine is warmer than it actually is. If it smooths out as it warms up, then acts normally when it is warm, this would reinforce to me that the cooling sensor is starting to fail but is still reading within the computer's error tolerance. When the engine is cold the computer increases the injection pulses, which kind of acts like a choke. If the computer thinks it's cold when it isn't, then it will use warm engine pulses instead of cold which will act like a cold engine with a carb with no choke.

Another possibility is the EGR valve is getting stuck open. The EGR is supposed to remain closed until the engine is warmed up. If it's getting stuck open then it's dumping exhaust into the intake when the engine can't handle it. An EGR that's stuck open can cause hesitation, stalling and idling problems when cold.

Hope this helps.
 
No, really it seems to run fine. There's no chugging or lean stumble. It just doesn't pick up enough engine speed in gear to move the car. Maybe it's lean and it's masked by the ETC system, but there are no lean codes, no codes at all. I can check the ECT with my scangauge. Cars with a stuck open EGR usually run really crappy at idle, and the EGR is only about 1 year old. It never stumbles or idles crappy.
 
No, really it seems to run fine. There's no chugging or lean stumble. It just doesn't pick up enough engine speed in gear to move the car. Maybe it's lean and it's masked by the ETC system, but there are no lean codes, no codes at all. I can check the ECT with my scangauge. Cars with a stuck open EGR usually run really crappy at idle, and the EGR is only about 1 year old. It never stumbles or idles crappy.

You'd definitely have a code on display if your EGR was flowing while cold.
 
That'll point more towards a failing temp sensor then. They are a resistance based device, with higher resistance when cold, lower when hot. If it's developing an intermittent internal short then it'll show low resistance when cold, thus telling the car that the engine is warm when it isn't which will cut the fuel enrichment. It can be shorted yet still fall within the specs the computer is looking for.
 
I've had the car 5 years. I am very familiar with the car, I understand there is a rev limiter, and it revs lazy in park and neutral even in perfect working condition. This is something more.

Did you read my first post, or do you suffer from poor reading comprehension? Is it normal for your car not to move when you press on the gas pedal in gear/reverse?

You failed to state in your first post, that it would not move in reverse. You also said that it acts normal in drive. The only thing you clearly stated, is that is revs slow in park and neutral. You were acting as though you just discovered the rev limiter. You never stated you have had the car for 5 years. My reading comprehension is fine, thank you. Maybe you should go back and read your first post. You seem to be the the one that has a communication problem, in clearly stating the issue you are having with the car. You didn't mention until you slammed me, that the issue was in gear/reverse. Thank you for the claification.

Telco may be on to something. I don't know. Since you just had tranny work done 6 months ago, I would be suspect of that. If I am not reading too much into what you have said, the tranny work was done, because of the same issue??? There are multiple micro switches in the shifter console, that control the electronic functions of the transmission.

On, the drivers side of the tranny, there is a gear selector/neutral saftey switch. This would function for park/neutral start only, reverse lights, and tell the computer when to engage the rev limiter. Maybe when the tranny was installed, they didn't get everything perfectly adjusted. There is still a cable linkage from the shifter to the tranny on these cars. Maybe the detents in your shifter console are slightly off, due to the cable being out of adjustment. Maybe over the last 6 months, as parts have settled in, the cable has gotten further out of adjustment.

To me, from what little info you have given, it seems as thought the car is acting as if it's still in park or neutral, thus the low power/rpm. If you put it in D4, (instead of D5), does it act normal? Try putting the selector in Reverse, and then gently feathering the slector towards neutral or park, while still keeping reverse gear engaged. Do you have full power then? Maybe you should take it back to where you had the tranny replaced, and have them look at it. Hopefully it is still under warranty. I may be wrong about my suggestions and ideas, but I am still trying to help, even after you were an a$$ to me.

Have a nice day. :)
 
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You failed to state in your first post, that it would not move in reverse. You also said that it acts normal in drive. ...

From the first post.
My wife thought the trans was having issues (it was replaced 6 months ago along with the ECM), as it wouldn't move.

It's okay, I sometimes miss stuff on first read too.

Never say never, but I don't think it would be the neutral switch. The car would still move, even still at just engine idle. Also, the gear indicator would not have been correct (R or D), and no issue with the indicator was stated.
 
Our '03 LS8 has a newer issue. Sometimes after a cold start. It won't rev. My wife thought the trans was having issues (it was replaced 6 months ago along with the ECM), as it wouldn't move. After a few seconds, it did/does. I started playing with it and figured out it won't rev as you give it throttle in park or neutral. Once it does start to rev, it's extremely slow. It probably takes 2.3-3 seconds to get to the 3000 rpm P/N rev limiter. The car drives fine otherwise and seems to be completely normal in drive. Any thoughts? Could the ETC actually be failing or dirty/gummy?

My 04 has done something similar, but only once and that was a year or two ago. After my wife stopped at a stop sign, it wouldn't respond to the gas pedal at all. She had to turn the engine off and restart for it to work correctly. The odd thing to me was that there was no check engine light, no ETC warning, and no OBDII code (pulled with a scanner able to read all codes).
 
To me, from what little info you have given, it seems as thought the car is acting as if it's still in park or neutral, thus the low power/rpm. If you put it in D4, (instead of D5), does it act normal? Try putting the selector in Reverse, and then gently feathering the slector towards neutral or park, while still keeping reverse gear engaged. Do you have full power then? Maybe you should take it back to where you had the tranny replaced, and have them look at it. Hopefully it is still under warranty. I may be wrong about my suggestions and ideas, but I am still trying to help, even after you were an a$$ to me.

Have a nice day. :)

what he said. i didnt buy one particular LS because of this exact scenario. LS looks like its in drive, feels like it went into drive, dash says its in drive, computer thinks its in N. Same for d5 vs d4, R vs N, etc. Notably, the tranny had been pulled 10k miles earlier per the marking on the bottom of it
 
I am pretty sure it's going into gear. There is a clunk. The trans was rebuilt because it was shuddering into 3rd and was slamming 4th. There was also a surging rolling on the gas at expressway speeds. I was pretty sure the surging was a failing torque converter. I was warned it would probably also need a PCM, which it did. I wasn't going to put a new TC in a 180,000 mile trans without having it rebuilt. Likely just a PCM/flash would have fixed most of the shifting issue. The servo bores were very warn, and the shifts were slow and clunky. It was $2100 total, and the trans shifts better than it ever has. I did speak with the trans shop, and they need to see it malfunctioning, which will be hard to do since it doesn't always malfunction.

Obviously, I'm not sure what the issue is and am hoping that this is an issue that has been resolved before. It's never happened going into drive, but the car is almost always pulled straight in and needs to be backed out. So, cold starts always see reverse.
 
Sounds like a stick of dynamite will solve the sticking problem.
 
Pleas Help

I also have an 03 Lincoln Ls 3.9L and I've been able to bring it's RPM's up between 2000-2500 no problem when in neutral, for the purpose of bleeding the cooling system. For some reason, tonight when pressing on the gas pedal while in neutral, I'd get no response. I needed to bleed the cooling system because I had to replace the expansion tank.

My questions:
1. Why am I not able to bring the RPM's up anymore when applying throttle while in neutral?
2. Where can I get a quality expansion tank? (I've had to replace the expansion tank 3x in less than a year. After around 2-3 months, a leak would come from the seems. Each expansion tank was purchased at autozone, luckily my 2nd one came with a lifetime warranty. It's a nightmare.)

Also today as I came home from school, coolant was leaking out of the lid from the expansion tank. I don't know why it would because coolant was filled to its proper level while the car was cold, between the min and max. I also heard a bubbling sound coming from the thermostat housing. I've owned this car since 08 and I love it. This past 2 years has been horrible since I've been having issues with the cooling system. Any input is greatly appreciated, thanks.
 
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1. Not sure. Try applying the gas pedal more slowly.
2. This same issue is going to keep happening as long as you keep getting Dorman or rebranded Dorman degas bottles. AFAIK, there are only two degas bottles made for the LS, One is made by Dorman but goes by several different brands. The other is Motorcraft. The Dorman made ones only seem to last a few months. The Motorcraft ones go six years, give or take. Pay the extra, get the Motorcraft.
3. The Motorcraft degas bottle cap does not correctly fit the Dorman bottle. Also, you will need to replace just about all of the plastic cooling system parts. You are not an exception to what just about everyone else has had to do...
http://www.lincolnvscadillac.com/forum/showthread.php?91092-GenII-LS8-Cooling-System-Overhaul
After this, you should have five to ten years without cooling system problems.
 
I've never fixed mine, but I believe my issue is caused by vacuum leaks between the plastic intake manifold and the aluminum lower intake. There're square o-rings that seal that up. They aren't serviced by Ford/Jaguar, but they can found on eBay for roughly $160. I used a smoke machine to find my leaks. The car also occasionally sets lean trouble codes. It's worse in cold weather on cold starts, and in the cold the idle surges until the car warms up.
 

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