n1das
TDIClub Enthusiast, Veteran Member
- Joined
- Jun 11, 2002
- Location
- Nashua, NH, USA
- TDI
- 2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
TB squish-squish-squish-squish sound...I very narrowly averted a timing belt failure! /images/graemlins/shocked.gif
If your TDI has been making a soft "squish-squish-squish-squish" or "slosh-slosh-slosh-slosh" sound coming from the TB area, you may have a ticking time bomb under the hood! If so, get it checked ASAP! Pay particular attention to how the belt tracks through the entire TB path because it may be mis-tracking. /images/graemlins/shocked.gif
I just had my 80k mile first TB change done and I narrowly averted a TB disaster. My TB was one that was making a squishing sound and I found it was ready to fail at any moment! The belt was mis-tracking and being shaved by the TB tensioner like a knife on the edge of the belt. My belt was badly frayed and there were belt fragments and dust everywhere under the TB covers. It was amazing that I was still driving my TDI in this condition! /images/graemlins/shocked.gif I've included some pics of the belt and what I found in the engine.
First off, I can't thank Herm TDI enough for his excellent work done during my 80k mile first scheduled TB change! /images/graemlins/cool.gif He is a true expert on TDIs when it comes to TB changes. He does excellent work and his rates are reasonable. Herm does everything by the book and carefully checks and double-checks all of his work every step of the way, leaving absolutely nothing to chance. Best of all, I got to participate in the wrenching session and witness every step of the TB change job. After participating in my 80k mile first TB change, I have a much better appreciation for WHY you should avoid VW dealers at all costs for a TB change and have an expert like Herm do the job. It was a good wrenching session this past Saturday 12/13/03. It doesn't get any better than this. I will definitely be going back to Herm TDI in Maine for future work. /images/graemlins/laugh.gif
I've seen several threads in the past asking about a "squishy" or "sloshy" sounding TB, but nobody was able to give any definitive answers as to the root cause. Some believed it may be a due to a noisy TB tensioner or serpentine belt tensioner. Some said it's somewhat normal because some TDIs like mine have done it almost since it was new. I first noticed mine making a soft squish-squish-squish sound at around 15-20k miles. It was loudest when cold and made 1 squish sound per rotation of the TB. The sound was most noticeable at idle. Also, I had neglected to regularly pop the TB cover off and inspect the TB for any signs of problems. Like others, I wrote it off as a normal sound because I've heard "normal" belt sounds from cars before. The result is I've driven about 60k miles with my squishy-sounding TB and never checked it. This was a BIG mistake on my part! /images/graemlins/blush.gif /images/graemlins/eek.gif
My TDI: Black 2002 Golf TDI 5-speed, 4-dr, GLS trim, 80900 miles (now over 81k miles).
The car has been absolutely excellent since new. No problems to date, or so I thought! My TB was badly frayed along the outer edge around the entire length of the belt. All 3 of my TB rollers were found to be badly worn, which seems strange for a 2002 A4 TDI with "only" 80k miles. Normally these rollers are supposed to last until the second TB change at 160k miles. 90% of my driving has been agressive highway miles, regularly driving it like I stole it. I also regularly do WOT runs up to 4000RPM to help keep the air intake cleaned out.
The bearings in the TB rollers were badly worn enough that the rollers were loose and causing the belt to mis-track and rub against the flange of the TB tensioner pulley. The TB tensioner also may have caused the belt to mis-track. It was like holding a knife against the edge of the timing belt as it rotated through the TB path. I believe the root cause of the squish-squish-squish-squish sound was the sound of the belt being shaved by the TB tensioner pulley.
After studying the TB and where it was tracking, we came to the conclusion that the flange on the TB tensioner pulley was the ONLY THING keeping the TB from de-railing from the sprockets! Also, the TB tensioner had totally backed off all tension on the TB. There was absolutely no tension left on the TB whatsoever. This might explain why I've noticed the squish sound had quieted down over the last 20k miles or so. This timing belt was literally ready to fail at any moment! I realized I've been driving around for who knows how long with a ticking time bomb under the hood! (I dragged my jaw on the floor of Herm's garage!) Herm emphatically said "DO NOT DRIVE THIS!!"
The two small TB rollers spun freely but felt loose and sloppy. You could easily feel the play in the bearings. They also felt like they were almost totally dry of any lubrication. The large TB idler bearings felt "crunchy" and binding up as you spun the idler around by hand. Sometimes it would even squeal and howl when you spun it.
We called two VW dealers in the area to try to get some new TB rollers, but with no luck. They were out of stock, and the earliest we could get new parts would be Wednesday. We did not want to attempt to use my original rollers because it would damage the new TB the first time the engine was started. Given that I needed my car and can't get new roller parts for several days, we elected to install a set of used rollers that were in serviceable condition and in far better shape than my original rollers. We had to do this just to get my TDI engine back together and running again.
I was very lucky that Herm just "happened" to have a set of TB rollers available. This is what's holding me over while I have a set of new TB rollers on order. I'll be going back to Herm's place to have the new rollers installed after they arrive. I could probably go quite a while on the set of used rollers, but I'm not going to chance it. The part that's a real PITA is that we'll have to do the whole disassembly operation again to install these rollers. But I'll sleep better knowing the job is done 100% correctly and everything in the entire timing belt path has been replaced with new parts.
My water pump was in good shape but it was replaced with a new one during the TB change as a preventive measure. Although the WP was in good shape, it may not make it to the next sheduled TB change. I knew it was a good idea to replace the WP during the TB change, but we weren't expecting to have to replace the TB rollers so soon.
Lessons learned:
===============
* Regularly inspect the TB at each oil change interval (every 10k miles). Pay close attention to how the belt tracks through the entire TB path. If the TB is mis-tracking, get it fixed ASAP.
* Check the TB tensioner to make sure the TB is tensioned properly.
* Pay attention to any noises coming from the timing belt or any TB-related parts. A squish-squish-squish-squish or slosh-slosh-slosh-slosh sound is the sound of a timing belt that is mis-tracking and being shaved by the TB tensioner. This is a ticking time bomb under the hood!
* Consider doing an A4 TB change at 60k mile intervals instead of 80k intervals on an '02 or 100k miles on an '03. From what I've seen with my TB at 80k miles, I wouldn't trust the TB to go 100k miles in an '03 TDI.
* During any scheduled TB change, replace ABSOLUTELY EVERYTHING in the TB path with new parts: TB, TB tensioner, water pump, and the 3 TB rollers. It's cheap insurance and good preventive maintenance.
* Avoid VW dealers at all cost. Dealers will simply do a half-a$$ed "mark and pray" TB change, neglecting to change the water pump, rollers, and camshaft seal. We already know they don't always replace the TB tensioner. We know they'll reuse the engine mount bolts which are supposed to be used only once. We know dealers are reusing these bolts because the dealers normally don't keep these bolts in stock. Had a VW dealer done my TB change, the new belt would soon be damaged by my bad rollers and would likely fail a few thousand miles after the TB change. All bets would be off with regard to how well the engine would run before the TB failure because of the (incorrect) "mark and pray" method used. Also who knows how the engine mount bolts would hold up because they were reused instead of replaced with new bolts.
* Go to an expert like Herm TDI, Car54, or Drivbiwire for all TDI TB changes. Otherwise do it yourself if you're up to it. Drivbiwire's TB change document is a good starting point to use as a guideline. Don't go to a vW dealer!
Here are some pics of the original timing belt and the belt fragments we found in the engine. This is some real scary stuff considering I was driving around for who knows how long with it like this! /images/graemlins/eek.gif /images/graemlins/shocked.gif
Here are some pics with the original TB still in place in the engine:
Here are closeup pics of the TB showing the frayed edge and damaged teeth:
My TDI now runs better and is noticeably peppier than it was when new. Herm got the injection timing set slightly on the advanced side of spec, but within spec. My original timing was set right to spec and maybe a hair on the retarded side of the spec. It runs GREAT now with how Herm set it up!
Again, I can't thank Herm TDI enough for his expertise! It's scary to think I narrowly averted a TB disaster!
~ n1das
If your TDI has been making a soft "squish-squish-squish-squish" or "slosh-slosh-slosh-slosh" sound coming from the TB area, you may have a ticking time bomb under the hood! If so, get it checked ASAP! Pay particular attention to how the belt tracks through the entire TB path because it may be mis-tracking. /images/graemlins/shocked.gif
I just had my 80k mile first TB change done and I narrowly averted a TB disaster. My TB was one that was making a squishing sound and I found it was ready to fail at any moment! The belt was mis-tracking and being shaved by the TB tensioner like a knife on the edge of the belt. My belt was badly frayed and there were belt fragments and dust everywhere under the TB covers. It was amazing that I was still driving my TDI in this condition! /images/graemlins/shocked.gif I've included some pics of the belt and what I found in the engine.
First off, I can't thank Herm TDI enough for his excellent work done during my 80k mile first scheduled TB change! /images/graemlins/cool.gif He is a true expert on TDIs when it comes to TB changes. He does excellent work and his rates are reasonable. Herm does everything by the book and carefully checks and double-checks all of his work every step of the way, leaving absolutely nothing to chance. Best of all, I got to participate in the wrenching session and witness every step of the TB change job. After participating in my 80k mile first TB change, I have a much better appreciation for WHY you should avoid VW dealers at all costs for a TB change and have an expert like Herm do the job. It was a good wrenching session this past Saturday 12/13/03. It doesn't get any better than this. I will definitely be going back to Herm TDI in Maine for future work. /images/graemlins/laugh.gif
I've seen several threads in the past asking about a "squishy" or "sloshy" sounding TB, but nobody was able to give any definitive answers as to the root cause. Some believed it may be a due to a noisy TB tensioner or serpentine belt tensioner. Some said it's somewhat normal because some TDIs like mine have done it almost since it was new. I first noticed mine making a soft squish-squish-squish sound at around 15-20k miles. It was loudest when cold and made 1 squish sound per rotation of the TB. The sound was most noticeable at idle. Also, I had neglected to regularly pop the TB cover off and inspect the TB for any signs of problems. Like others, I wrote it off as a normal sound because I've heard "normal" belt sounds from cars before. The result is I've driven about 60k miles with my squishy-sounding TB and never checked it. This was a BIG mistake on my part! /images/graemlins/blush.gif /images/graemlins/eek.gif
My TDI: Black 2002 Golf TDI 5-speed, 4-dr, GLS trim, 80900 miles (now over 81k miles).
The car has been absolutely excellent since new. No problems to date, or so I thought! My TB was badly frayed along the outer edge around the entire length of the belt. All 3 of my TB rollers were found to be badly worn, which seems strange for a 2002 A4 TDI with "only" 80k miles. Normally these rollers are supposed to last until the second TB change at 160k miles. 90% of my driving has been agressive highway miles, regularly driving it like I stole it. I also regularly do WOT runs up to 4000RPM to help keep the air intake cleaned out.
The bearings in the TB rollers were badly worn enough that the rollers were loose and causing the belt to mis-track and rub against the flange of the TB tensioner pulley. The TB tensioner also may have caused the belt to mis-track. It was like holding a knife against the edge of the timing belt as it rotated through the TB path. I believe the root cause of the squish-squish-squish-squish sound was the sound of the belt being shaved by the TB tensioner pulley.
After studying the TB and where it was tracking, we came to the conclusion that the flange on the TB tensioner pulley was the ONLY THING keeping the TB from de-railing from the sprockets! Also, the TB tensioner had totally backed off all tension on the TB. There was absolutely no tension left on the TB whatsoever. This might explain why I've noticed the squish sound had quieted down over the last 20k miles or so. This timing belt was literally ready to fail at any moment! I realized I've been driving around for who knows how long with a ticking time bomb under the hood! (I dragged my jaw on the floor of Herm's garage!) Herm emphatically said "DO NOT DRIVE THIS!!"
The two small TB rollers spun freely but felt loose and sloppy. You could easily feel the play in the bearings. They also felt like they were almost totally dry of any lubrication. The large TB idler bearings felt "crunchy" and binding up as you spun the idler around by hand. Sometimes it would even squeal and howl when you spun it.
We called two VW dealers in the area to try to get some new TB rollers, but with no luck. They were out of stock, and the earliest we could get new parts would be Wednesday. We did not want to attempt to use my original rollers because it would damage the new TB the first time the engine was started. Given that I needed my car and can't get new roller parts for several days, we elected to install a set of used rollers that were in serviceable condition and in far better shape than my original rollers. We had to do this just to get my TDI engine back together and running again.
I was very lucky that Herm just "happened" to have a set of TB rollers available. This is what's holding me over while I have a set of new TB rollers on order. I'll be going back to Herm's place to have the new rollers installed after they arrive. I could probably go quite a while on the set of used rollers, but I'm not going to chance it. The part that's a real PITA is that we'll have to do the whole disassembly operation again to install these rollers. But I'll sleep better knowing the job is done 100% correctly and everything in the entire timing belt path has been replaced with new parts.
My water pump was in good shape but it was replaced with a new one during the TB change as a preventive measure. Although the WP was in good shape, it may not make it to the next sheduled TB change. I knew it was a good idea to replace the WP during the TB change, but we weren't expecting to have to replace the TB rollers so soon.
Lessons learned:
===============
* Regularly inspect the TB at each oil change interval (every 10k miles). Pay close attention to how the belt tracks through the entire TB path. If the TB is mis-tracking, get it fixed ASAP.
* Check the TB tensioner to make sure the TB is tensioned properly.
* Pay attention to any noises coming from the timing belt or any TB-related parts. A squish-squish-squish-squish or slosh-slosh-slosh-slosh sound is the sound of a timing belt that is mis-tracking and being shaved by the TB tensioner. This is a ticking time bomb under the hood!
* Consider doing an A4 TB change at 60k mile intervals instead of 80k intervals on an '02 or 100k miles on an '03. From what I've seen with my TB at 80k miles, I wouldn't trust the TB to go 100k miles in an '03 TDI.
* During any scheduled TB change, replace ABSOLUTELY EVERYTHING in the TB path with new parts: TB, TB tensioner, water pump, and the 3 TB rollers. It's cheap insurance and good preventive maintenance.
* Avoid VW dealers at all cost. Dealers will simply do a half-a$$ed "mark and pray" TB change, neglecting to change the water pump, rollers, and camshaft seal. We already know they don't always replace the TB tensioner. We know they'll reuse the engine mount bolts which are supposed to be used only once. We know dealers are reusing these bolts because the dealers normally don't keep these bolts in stock. Had a VW dealer done my TB change, the new belt would soon be damaged by my bad rollers and would likely fail a few thousand miles after the TB change. All bets would be off with regard to how well the engine would run before the TB failure because of the (incorrect) "mark and pray" method used. Also who knows how the engine mount bolts would hold up because they were reused instead of replaced with new bolts.
* Go to an expert like Herm TDI, Car54, or Drivbiwire for all TDI TB changes. Otherwise do it yourself if you're up to it. Drivbiwire's TB change document is a good starting point to use as a guideline. Don't go to a vW dealer!
Here are some pics of the original timing belt and the belt fragments we found in the engine. This is some real scary stuff considering I was driving around for who knows how long with it like this! /images/graemlins/eek.gif /images/graemlins/shocked.gif
Here are some pics with the original TB still in place in the engine:
Here are closeup pics of the TB showing the frayed edge and damaged teeth:
My TDI now runs better and is noticeably peppier than it was when new. Herm got the injection timing set slightly on the advanced side of spec, but within spec. My original timing was set right to spec and maybe a hair on the retarded side of the spec. It runs GREAT now with how Herm set it up!
Again, I can't thank Herm TDI enough for his expertise! It's scary to think I narrowly averted a TB disaster!
~ n1das
