[gminnebo]

Looking for thoughts about this clacking noise my Daughters PT GT is making to help me diagnose for repairs.

My daughter has a 2006 PT GT 2.4 HO turbo automatic, 130k, it started making this clacking noise intermittently, it's not every time it starts, but if it does make the noise, it is on start up (not necessarily cold start up). Until now at least it has been that way, this last time it never stopped and the car was idling for 11 minutes.

Car was in pretty rough shape when I purchased it, but the engine ran strong with no unusual noises, it had a salvage title because it had been rear ended, I spent a lot of time fixing the rear, cleaning the interior (ick) and getting the engine up to current mileage services recommendations, including the timing belt.

No engine codes since all of the work a year ago, the codes I had then were related to the power steering pressure switch. The PS pump was shot and leaking everywhere.

As noted it is my daughters car, and when I have had the car to work on, it hasn't made the noise, so I have never heard it except for the below videos. I am working on getting the car to my house this weekend to look at (towing not driving).

Thanks in advance for your thoughts.

Engine Details I know of:

• New timing belt and associated recommended parts, pullys water pump, mounts etc. 1 year ago
• New plug wires, spark plugs when timing belt was changed. 1 year ago
• New valve cover seal 1 year ago.
• oil and filter
• Replaced the power steering pump lines and pressure sensor 1 year ago.
• New radiator 1 year ago.
• New coil, plugs and wires, 2 months ago (was hoping that the noise was a misfire, although I had no codes.

Here are a series of videos of the noise, the first videos are before I gave it a tune up (plugs, wires and coil):

The first time we heard it before a tune up:

After the tune up:

Last recording, Noise never stopped (11 minutes) shut car off and haven't driven or started, yesterday 11/24/21"

 

[ImperialCrown]

Is it loudest at the front of the engine? In one video it was doing a double-tap, like a loose timing belt hitting the inside plastic timing belt cover? In the last video, the tap-rate is at half speed.
It doesn't sound internal, like a wrist pin or lifter. They follow engine speed and are usually consistent.

 

[djsamuel]

My PT had a sound almost identical to that. One of the bolts attaching the torque converter to the flexplate had backed out. I got underneath, and added locktite (blue) to each bolt and tightened everything back up. No problems since. Just a long shot, but wanted to post it just in case.

Here is a video I made at the time:

 

[gminnebo]

Is it loudest at the front of the engine? In one video it was doing a double-tap, like a loose timing belt hitting the inside plastic timing belt cover? In the last video, the tap-rate is at half speed.
It doesn't sound internal, like a wrist pin or lifter. They follow engine speed and are usually consistent.

Yes, front of engine, I had my daughter place her finger on the timing cover, she said she could feel the noise, she also put her finger on the oil filler cap and felt nothing. I’m thinking timing belt, or possibly a bearing on one of cam shafts… cost wise I’m hoping for the belt… as hard a job as that is…

 

[djsamuel]

Yes, front of engine, I had my daughter place her finger on the timing cover, she said she could feel the noise, she also put her finger on the oil filler cap and felt nothing. I’m thinking timing belt, or possibly a bearing on one of cam shafts… cost wise I’m hoping for the belt… as hard a job as that is…

When the flexplate bolt loosened on my PT, I thought for sure it was coming from the front of the engine. Someone suggested the flexplate, thinking it may have been cracked, and that's why I checked. It doesn't sound like a cam bearing would be making that noise, but it is not that difficult to get the cover off and check.

 

[gminnebo]

When the flexplate bolt loosened on my PT, I thought for sure it was coming from the front of the engine. Someone suggested the flexplate, thinking it may have been cracked, and that's why I checked. It doesn't sound like a cam bearing would be making that noise, but it is not that difficult to get the cover off and check.

Will definitely look there, is there an easy access to check, in my old 2.2 2.5 turbo days I can’t remember if there was a access under it…

 

[djsamuel]

Will definitely look there, is there an easy access to check, in my old 2.2 2.5 turbo days I can’t remember if there was a access under it…

Yes, it is easy to get to. You just need to remove an access plate underneath and then you can get to the bolts. I just used a large screwdriver to slowly rotate the flexplate by engaging with the gear teeth and slowly turning it.

 

[djsamuel]

If you watch my video above regarding the noise from the flexplate, notice how it changed between drive and reverse. I imagine if the bolts are loose enough it won't make any difference, but perhaps you can check that to see if it does. It would help to confirm the problem.

 

[the3dgm]

I'd agree with Imperial Crown. To me it is more of a 'slapping' sound than an internal metallic clicking noise. The fact that the 'rhythm' changes, suggests, to me, something moving. Like the belt flopping or a bolt backing out and being hit differently each time. Just my thoughts.

 

[MChat]

The slapping sound makes me think it might be a worn out balance shaft assembly chain.
2.4L chrysler PT Cruiser metallic knocking sound in engine - YouTube

Did you replace the timing belt tensioner when you replaced the belt? If that is worn out, it might cause the timing belt to "slap around" as well.

 

[gminnebo]

The slapping sound makes me think it might be a worn out balance shaft assembly chain.
2.4L chrysler PT Cruiser metallic knocking sound in engine - YouTube

Did you replace the timing belt tensioner when you replaced the belt? If that is worn out, it might cause the timing belt to "slap around" as well.

Yes new tensioner, but I am leaning towards something going amiss related to the timing belt, thanks.

 

[chuzz]

Depending on where you got your timing set, I also vote for a defective tensioner. It sure sounds like it's "bouncing" just a little bit to me. BUT, you need to know that I'm not nor have I ever worked as a mechanic. Just been pulling my own wrenches for 50 years.

 

[dana44]

Since the noise isn't constant, it could be the plastic valance that goes in front of the air conditioner pump on the bottom front edge of it. Sometimes they get out of wack and can make a noise like this.

 

[gminnebo]

Thanks Everyone, I now have the car in my garage, it wasn’t making the noise when I got it and towed it home (dolly), but it started making the noise when I pulled it into my garage (so not on start up but after running for about 5 minutes). Still not sure what it is, but I plan to inspect everything I worked on or replaced last fall, starting with the easiest jobs first… I will report here when/if I find the issue.

 

[gminnebo]

Update: first its really cold out here in West MI brrr.

I think I found the smoking gun, it looks like the Serpentine belt for the Power Steering and AC isn't tracking straight on the PS pump pulley, and when it snaps back into place the tensioner makes a pretty distinct clank, I haven't caught the noise happening on its own with the pulleys exposed to confirm, but I can push the belt onto the pulley fully with the engine running and the tensioner will clank and then the belt is back to being off a couple grooves (seems to vary from one groove to two groves off). Not sure how to correct the alignment... but I am going to replace the tensioner and the belt, and during that process, I'll see if I can figure out why its out of alignment. who knows maybe I bent the two mounts that the pump is sandwiched between when installing the new/used pump... or maybe the pump wasn't a perfect fit (was from a SRT4).
The belts not coming completely off so I'm not sure I'll get to worked up about it after the work, if it still happens, now that I know it is not necessarily something catastrophic to the engine.

I will follow up again when I have the parts and the work is done...

Thanks again for the ideas, and djsamuel if there is an access plate on the Auto transmission for this 2.4 turbo... I can't find it... maybe buried under the turbo intercooler and power steering lines but nothing even remotely obvious.

 

[MChat]

if there is an access plate on the Auto transmission for this 2.4 turbo... I can't find it... maybe buried under the turbo intercooler and power steering lines but nothing even remotely obvious.

Yes, the intercooler pipe and power steering lines are in the way. IIRC, once the lower pipe is removed, you have to remove the two bolts holding the pipe on and two other bolts that go through the cover to the transmission (one near the starter and one on the backside). The one by the starter, you have to also loosen the bolts that hold the bracket onto the engine block.

This is probably an SRT-4, but its the cast aluminum plate that the intercooler pipe and P/S lines are bolted to.

 

[djsamuel]

Yes, the intercooler pipe and power steering lines are in the way. IIRC, once the lower pipe is removed, you have to remove the two bolts holding the pipe on and two other bolts that go through the cover to the transmission (one near the starter and one on the backside). The one by the starter, you have to also loosen the bolts that hold the bracket onto the engine block.

This is probably an SRT-4, but its the cast aluminum plate that the intercooler pipe and P/S lines are bolted to.
View attachment 84622

Thanks for posting this. I didn't realize the intercooler pipe was there.

 

[Sooner PT]

NOT THAT IT HELPS YOU MUCH, BUT...........

In installing some decent horns on my new Convertible yesterday, I discovered (saw with better access after the wheelwell liner was pulled back)..................
The inner plastic shroud that protects the serpentine belt was loose, and the bottom pulley of the serpentine belt had worn a hole through it; such that I could see about 1/3 of the pulley!!!!
I now wear hearing aids, so it would have to be loud for me to heard the rubbing.
Also...it's my 2nd PT to have the passenger side 17 inch tires wearing a hole through the inner wheelwell liner towards the center.
So, that's what I'll work on tomorrow, from underneath in my storm shelter!

 

[gminnebo]

Well, I replaced the tensioner, not sure if it was bad, and the A/C PS belt, given the difference in length (new vs old), I suspect the belt was done, odd that there was no squealing though.

Anyway, with the new belt and tensioner, the belt no longer drifted out of line on the PS pulley so I'm calling it fixed (fingers crossed).

Really feel like I dodged a bullet here, that timing belt is easily a 8 to 12 hour job on this car... (4 hours to get the timing set correctly... LOL)

Thanks again for the ideas and thoughts, definitely were on the right track with the belt slapping and loose comments.

 

[frankiearnone83]

When the flexplate bolt loosened on my PT, I thought for sure it was coming from the front of the engine. Someone suggested the flexplate, thinking it may have been cracked, and that's why I checked. It doesn't sound like a cam bearing would be making that noise, but it is not that difficult to get the cover off and check.

Pts do not have cam bearings. The head is line honed for the cam shafts