Cadillac Owners Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
Haven't seen this exact problem here; a couple of weeks ago I noticed the trunk was opening slower than normal, and now it barely opens at all, have to help it with my hand, especially when it's hot out. However it seems to work normally when putting the top down. Please help - thanks!
 

·
Registered
Joined
·
2,439 Posts
Could be expensive, could be cheap. If you have a powerful flashlight, this would be a good job for it.

Let's start with cheap: Your electrical system isn't putting out enough power. Always move the top while the engine is running. You can do about three cycles of the top on battery power alone and not be able to start the car.

Another easy one: The Folding Top hydraulic oil reservoir is low. This is inexpensive; you just add fluid. It's located in the left/rear tub in the trunk, buried under the rat fur carpet. There's a min/max set of fill lines on the side of the reservoir. You can use the search function here to locate the part number for replacement oil or ask back.

If the reservoir is low, this begs the question: Why? There could be a hydraulic leak somewhere in the car. To say this is a mess is an under-statement, especially if it happens above the headliner and pools up there. You would need a new hydraulic line, and replacement of damaged interior parts from the oil. This could get pricey.

Look for a failing hydraulic cylinder that might show visible signs of leaking. Again, do a thorough visual inspection to see if there are any tell-tale signs of oil build-up. This is where flashlights can start to pay for themselves.

Another cheap one: a faulty Position Sensor, reporting to the top's control module a top structural component is positioned where it isn't. Bad sensors are not uncommon in this car, and the repair costs are reasonable, especially compared to what comes next.

And even cheaper: A Re-Learn of the sensor data stored inside of the Folding Top Control module, which could occur because of the previous possibility. The sensors age with use and may change value over time, which contradicts what the module expects to "see." I had this happen a few weeks ago (same symptoms as yours, then it degraded to the point where the top would stop before completing the command.) It was a ten-minute Re-Learn. A dealership shouldn't charge more than an hour for labor to reset the module with a Tech II.


Nightmare 1.0: A Component of the Hydraulic Pump Assembly is failing. This can get fugly. A new hydraulic pump comes with an attached valve manifold and reservoir and runs north of $1600. A hydraulic valve can be sticking in the wrong position diverting less oil than required to lift the roof and it's the same. If you go that route, you'll need new O-rings for the hydraulic lines that need to be connected to the manifold. Labor on one of these jobs can be painful.

Nightmare 1.1: While you're inspecting the tub, make sure the drain line (or hole in some cars) isn't blocked. The XLR is notorious for water draining in that area and wiping out the electronics in there. You can lose the hydraulic pump, the Folding Top Control module and the Suspension module from flooding in there.

If it isn't one of the cheap/easy solutions, you should consider contacting a dealership with an XLR-certified tech. Write back with the cause/solution.

Good luck,
CC
 

·
Registered
Joined
·
5 Posts
Hey Dave, did you ever figure out what was going on with this? Mine is beginning to do it as well. It's not the convertible top, just the trunk lid, that moves slowly, and only upward, down moves fine.
 

·
Registered
Joined
·
2,439 Posts
Another thing that is relatively cheap to replace and easy to fix: There are a pair or gas-charged assist cylinders protruding from the bottom of the trunk to help the rear deck lid raise. These cars aren't getting any younger and the cylinders can lose their charge over time. If you have someone give a light "assist" on the rear deck lid while you raise it and it works like it use to, I'd start with replacing both of them.

CC
 

·
Registered
Joined
·
26 Posts
Discussion Starter #5
Wow - thanks for the advice, CC. I still have the problem, but I actually just had the car into a Cadillac dealer (made sure they had an XLR-certified mechanic on duty); I asked them to check the operation and even volunteered that maybe they could lubricate all the joints, but he came back saying there was nothig wrong. I'm sure going to check this, it rings true since the lid going up is the only problem. Plus, gas struts should be relatively cheap and I can change 'em myself. Thanks a bunch!
 

·
Registered
Joined
·
2,439 Posts
Dave,

The P/N for the (L/R) struts are: 88956655

They go for 44.63 from gmpartsdirect.com

This is one of the cheaper XLR repairs!

CC
 

·
Registered
Joined
·
26 Posts
Discussion Starter #7
CC - you are da best! Assuming this is the problem (and I really think there's a high probability it is since it's only the trunk lid and only when opening), it will be the third time you've saved me a bundle of cash on this car. Thanks again - I'll report back after I check it out.
 

·
Registered
Joined
·
2,439 Posts
Note that Dave Anderson's last post was 5 years ago, so don't be surprised if there's no response from him. Replace the air struts and you'll most likely resolve the problem.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #10
Actually CC, I'm here and I'm still driving my XLR - and it's amazing that you're still here helping people!

I've owned over forty cars and I rarely keep them longer than 2-3 years, but I've had this car since 2011 and have no plans to sell it; did a show just last year with it - people love this car, many of the guys have never seen one. Although I surf the discussions from time to time, I haven't participated mainly because I really haven't had any more problems - until just recently. First of all, yes, back then it certainly was the struts; replacing them fixed the problem instantly - my advice to Sammy is go for it; highly probable that's the solution.

Now I've got something similar happening but symptoms are not the same: trunk will open a few inches and then close again. However this is intermittent; sometimes works fine (always normal speed), other times up about six inches and then closes. First I thought cold weather might be contributing, especially if maybe the struts are getting weak again after five years, but even as it got warmer out it was still happening. Had it in to the dealer for something else (ABS light, which turned out to be - believe it or not - rodent damage to the wiring harness) but the trunk would not misbehave for them. Another thing is if you try to "help" it open, no way - it forcefully closes. Now I'm afraid to put the top down since if the trunk won't open, obviously the top will not go back up and I'll be stranded with an open top car. CC, if you're there I'm just now re-reading the possible solutions you listed in your original answer (above); I'm going to check all those, but if these specific symptoms light a bulb over your head please let me know. Thanks!
 

·
Registered
Joined
·
2,439 Posts
Nice to see you back here. Your intermittent opening top issue may be caused by several things. The cheapest would be a top relearn performed by your dealer. It takes longer to connect and configure the Tech 2 to the DLC port than it does to cycle the top once while the Folding Top Control module is reprogrammed with the sensor limit settings. You may also have a flaky sensor (this accounts for most of the top problems). Those aren't too expensive to replace.

Cold weather will affect top operation, but will be accompanied by an error message if it's too cold, so if you haven't seen that, I wouldn't worry about it. In extreme cases, the thermistor in the motor fails and has to be replaced.

Before you have a dealer diagnose the problem, manually open the top and inspect the hydraulic cylinders for any leakage. Verify the drain hole isn't plugged at the bottom of the motor compartment, and while you're there, ensure the hydraulic fluid level on the reservoir is between the min/max lines.

CC
 

·
Registered
Joined
·
26 Posts
Discussion Starter #12
Once again I'm very grateful for your advice, CC. Everything you've said makes a lot of sense; this will be my weekend project and I'll report back what I find.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #14
Back at ya, CC. I checked it on the weekend; hydraulic cylinders look good, fluid is up in the reservoir, and the motor compartment has always been dry - looks like I'm up for another trip to the dealer for a relearn and sensor check. Now I'm kind of miffed at the dealer I had it to; they just kinda said duhh, it didn't do it for us - why didn't they at least propose doing the relearn you mentioned? I think I'm going to take it to the other local dealer, and make sure they have a certified XLR mechanic available. Hell, half the fun of this car is the convertible feature - I want it reliable. I'll file a report when I get that done.
 

·
Registered
Joined
·
2,439 Posts
Back at ya, CC. I checked it on the weekend; hydraulic cylinders look good, fluid is up in the reservoir, and the motor compartment has always been dry - looks like I'm up for another trip to the dealer for a relearn and sensor check. Now I'm kind of miffed at the dealer I had it to; they just kinda said duhh, it didn't do it for us - why didn't they at least propose doing the relearn you mentioned? I think I'm going to take it to the other local dealer, and make sure they have a certified XLR mechanic available. Hell, half the fun of this car is the convertible feature - I want it reliable. I'll file a report when I get that done.
For anyone checking this thread out later, there's another component that can fail and cause your rear decklid to move slowly. Located just in front of the two hydraulic lift cylinders for the rear decklid are two, smaller pneumatic-assist cylinders that reduce the effort to move the decklid. These are covered by the rat fur carpeting on the sides of the trunk, so you have to peel it back to inspect/replace them. They are very inexpensive and can be replaced with simple tools.

With the youngest XLR over ten years old, it isn't uncommon to have these, (and the pneumatic struts for the hood) fail. Fortunately, you don't have to pay an arm and a leg to replace them.

CC
 

·
Registered
Joined
·
111 Posts
Good advice. Are these struts like the one at the pump and the one at the small compartment under the trunk?
I tried to change these first, but the deck is too heavy to hold it up without help from another person. Or is there a trick I didn't get?
 

·
Registered
Joined
·
26 Posts
Discussion Starter #19
C.C. and all - Well, I thought maybe I had a fix for my trunk problem. Suddenly had a dead battery, had to use the special key in the bumper to even get in; battery read 7.5V (after acting normally right up until then) and got only worse after hours on a charger. Replaced the battery, everything came up fine and I began to wonder if maybe the trunk was closing because something was seeing low voltage sometimes. Drove it for a couple of weeks exercising the trunk every time I stopped - no problem. Finally got the balls to put the top down, and when I tried to put it back up it hesitated; cycled it again and it closed properly. Tried to actuate the top later and got a "Top motor overheated" message as soon as I hit the switch - this was after the car had been sitting off for probably an hour.

So, now I know I definitely have a problem; I talked to both my local Cadillac dealers, couldn't even get a straight answer on whether they have a certified XLR mechanic. When I mentioned a re-learn procedure and checking the sensors, all I could get is "Well, we'll take a look at it"; "we don't see those very often" and "might be a lot of money." - Gives you a lot of confidence, you know? I guess I have no choice but to give it to one of them unless you have any other advice, C.C.; or are there any independent mechanics that would tackle this and do you know how I would find them?
 

·
Registered
Joined
·
2,439 Posts
Luckily, there's a much cheaper and better alternative Dave.

The thermistor in the hydraulic pump is a very cheap analog component which isn't meant to be replaced - GM would rather you replace the entire pump assy which costs a small fortune, plus labor.

This guy rebuilds pumps and leaky cylinders, replacing everything with higher quality, longer-lasting parts. Give him a shout and see if he can make your life easier: https://www.tophydraulics.com/cadillac/171-03-09-cadillac-xlr-hydraulic-pump.html

He's got a video to explain how to remove it here: https://www.youtube.com/watch?v=vySUjECUpSQ

CCC
 
1 - 20 of 26 Posts
About this Discussion
25 Replies
4 Participants
ccclarke
Top