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Rough Idle and some codes help.

hcloud13

Active Member
Joined
Aug 23, 2017
Messages
31
Location
Tampa FL
My XLR/V(s)
2004 Silver XLR
So yesterday I took off to the store and while at a light the CEL came one and the engine was running rough as hell at Idle. Came home and Figured I check it out today. Codes that popped are P0018, p0300, p0171, p0174. Crazy thing is when I started it and moved it out into the drive way it's running smooth as silk now. Looking into all the codes now, but if anyone can steer me in the right direction that would be great.
 
Just a quick check is your gas cap, I had it happen 2-3 times. I never thought a gas cap not on tight would cause the car to run rough, but it did.... I also think I remember a light on the dash panel came on CHECK GAS CAP!


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Intake manifold

I would check the intake manifold bolts. They seem to work loose on these cars. That could result in several of the codes you mentioned. Sounds like a vac leak somewhere. as stated the gas cap is a no brainer to check first then the manifold bolts
 
Some additional thoughts. Maybe ?

So yesterday I took off to the store and while at a light the CEL came one and the engine was running rough as hell at Idle. Came home and Figured I check it out today. Codes that popped are P0018, p0300, p0171, p0174. Crazy thing is when I started it and moved it out into the drive way it's running smooth as silk now. Looking into all the codes now, but if anyone can steer me in the right direction that would be great.

Last summer mine did exactly as you describe. After I checked everything (Intake Manifold Bolts, etc., as described here in other posts) as it did set a code, turned out it was water in the gas caused by just 'sitting' in the garage. Condensation. A can of 'gas dry' from O'Reilly's solved the problem. FYI, disconnecting the negative cable on XLR's does not erase the code(s). Must be erased with a scanner (mine an OBD II). Needless to say, they don't run well on water. :rolleyes: Problem has not resurfaced since.
 
I found the problem. It was the VVT oil timing solenoid inside the cam Phaser. Damn lock ring the size of a pin head blew out. 26805418_10214559770563748_1027496670088636148_n.jpg
 
VVT Oil Timing Solenoid.

I found the problem. It was the VVT oil timing solenoid inside the cam Phaser. Damn lock ring the size of a pin head blew out.View attachment 7710

So the rest of us also know, where in the heck is this located on the engine? More information please. What was involved in locating it and switching it out with a new one? Then of course one wonders where the little lock ring went when it broke? Ugh. :( Never a dull moment. --- Thanks for any additional information as it may help others on our forum.
 
So the rest of us also know, where in the heck is this located on the engine? More information please. What was involved in locating it and switching it out with a new one? Then of course one wonders where the little lock ring went when it broke? Ugh. :( Never a dull moment. --- Thanks for any additional information as it may help others on our forum.

Yeah, it was driving me crazy, thinking it was a vacuum leak, or a cam sensor or acuator, Even replaced the Crack sensor as any one of those could cause the problems and codes I had.

Here is a great video showing exactly what I did. It's not an XLR in the video, but it's the same set up. YouTube

And here is the part that took a crap.Duralast Engine Variable Timing Solenoid TS1032 - Read Reviews on Duralast #TS1032

Turns out this Solenoid is out of stock everywhere! Even Cadillac and GM couldn't order it for me. Called Dorman "The manufacture of the par" themselves and they said they would be available Jan 26th. So I wen't to a junk yard and pulled it from a Random Caddi that had the same engine.. and I'll order a new one when they are back in stock. I got the Solenoid for 1$ at the yard lol. So if the XLR ever starts running rough at idle and you get the codes p0300 and p0018/14/16... check this little guy first.
 
UGH! What a PIA

Yeah, it was driving me crazy, thinking it was a vacuum leak, or a cam sensor or acuator, Even replaced the Crack sensor as any one of those could cause the problems and codes I had.

Here is a great video showing exactly what I did. It's not an XLR in the video, but it's the same set up. YouTube

And here is the part that took a crap.Duralast Engine Variable Timing Solenoid TS1032 - Read Reviews on Duralast #TS1032

Turns out this Solenoid is out of stock everywhere! Even Cadillac and GM couldn't order it for me. Called Dorman "The manufacture of the par" themselves and they said they would be available Jan 26th. So I wen't to a junk yard and pulled it from a Random Caddi that had the same engine.. and I'll order a new one when they are back in stock. I got the Solenoid for 1$ at the yard lol. So if the XLR ever starts running rough at idle and you get the codes p0300 and p0018/14/16... check this little guy first.

Just watched the video. That guy is really through in his diagnosis and repair procedure. Lucky that he had the needed parts (used) from the old engine that had sucked a valve. Thank you so much for posting this info. --- My last question. How many miles on your engine when this broke? Thanks again!
 
Just watched the video. That guy is really through in his diagnosis and repair procedure. Lucky that he had the needed parts (used) from the old engine that had sucked a valve. Thank you so much for posting this info. --- My last question. How many miles on your engine when this broke? Thanks again!

Just hit 109k
 
I know this thread is old but wanted to share something that may help some one run down their vacuum leak.

My 2007 V was throwing codes for air intake etc...I kept looking for the leak and cleaning the MAF etc but the code would return. I then came across a video that helped me find the problem and it cost me 99 cents.

1. I took loose the plastic air intake from the intake just after the MAF (at the rubber connector) and placed a blue (harbor freight) rubber glove over the opening. Removed the large plastic cover and made sure the oil filler cap and dipstick were in tight.

2. Then disconnected the large vacuum line from the brake booster. Here comes the cool part ...I bought a 2 pack of swisher sweets for 99 cents and lit one up. Then just start blowing the smoke into the brake booster hose, covering the hose with your thumb between blows. The glove will start blowing up and creating some crankcase pressure with the smoke. Pretty soon I easily found my vacuum leak as the smoke was rising from the exact spot where the leak is. SIMPLE.

Mine was a loose hose clamp where the air intake metal piece is connected by a rubber connector that goes to the super charger. (hose clamp was loose) Reset light and has not come back.

Hope this common sense solution helps someone as much as it did me. FYI I do not smoke so if someone needs the other swisher, I got one for you.
 
Swisher Sweets resolve most problems in life. Thanks for the idea, I'm sure I will need to use it one day.
 

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