Engine noise when cold.

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
When the temperature is -4C or colder, I have this disturbing engine noise for the first 5 minutes or so. If I use my block heater, no noise or if the ambient temperature is above freezing, no noise. Its been doing this all winter, did not previously. Two service visits and dealer said "could not reproduce customer complaint." So I made this video and took it in for a third visit. They finally acknowledge a problem but no diagnosis. They are now saying bad fuel and recommend Shell fuel. Problem is, that is what I have been primarily using, and why is the "bad fuel" ok at warmer temperatures or when I use the block heater. I am somewhat distressed as my warranty is about to expire.

https://www.youtube.com/watch?v=tRGn9DZ3ZkI

The noise is worse too if the car sits for a few days without running, and then it runs roughs too for the first few minutes. Again, no issues if I use the block heater. There are no error codes on the computer.
 

passsattdi

Veteran Member
Joined
Jun 23, 2012
Location
NE PA
TDI
2012 Passat SEL Premium TDI
Collapsed lifter not pumping up? Kind of what it sounds like to me. Sounded a little louder with a little more peddle (power application in a higher gear). Cannot imagine that has anything to do with fuel. Sounds like 1 out of the 4 cyl.
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
that's a pretty loud clank- geeze! To my old school mechanic ears it sounds like piston slap or a rod- as its only clanking on 1 cyl on the powerstroke. Diesel noise can be hard to pin down- I thought for sure my Kubota ate a rod and it was only water in the fuel causing a horrible knock much like yours
 

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
If it is water in the fuel, does it make any sense that it only does it on a cold start with ambient temperature below freezing. Also the noise disappears after just a few minutes of driving. Would you recommend trying a product like "Power Service 911" which is supposed to take care of moisture?
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
That is a really bad sound. Is your car still under warranty?
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
Edit- I am putting my bet on a bad injector as its random, no knock on a few powerstrokes and heavy knock on the rest- lifters start noisy and slowly go silent as they pump up, rods just knock until they exit..... so a bad injector just over fueling one single cylinder is my bet
 
Last edited:

Fav40

Veteran Member
Joined
Nov 3, 2013
Location
Orange County NY
TDI
2014 Passat TDI SEL (BB 2/17/17) 2017 Passat V6 SEL Premium
Before listening to the video, I was going to say mine has more pronounced diesel clatter when cold. This is why I usually use the block heater at home and work, when cold.

That does sound like piston slap. It's deep and not good.


+1 on searching for another dealer who feels that's not "normal"
 

showdown 42

Veteran Member
Joined
Feb 16, 2012
Location
naples,FL
TDI
2016 TDI touareg
Establish a history with the dealer on this issue,so if you don't find the sillution the mileage won't be an issue for a future claim. By all means go to another dealer for help. Engine, Drive train should have longer than 3yrs and 36K miles coverage or what every you have in Canada.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Yes for about 1500km yet!
Get it in immediately. If it is a bad injector as jrm says, the noise is likely a result of uncontrolled injection timing and can cause long term engine damage if the problem goes uncorrected.

To me, this sounds like a bottom end problem or perhaps a bad cam/lifter problem. I've heard lots of bad injectors, but none have sounded like that.
 
Last edited:

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
Get it in immediately.
Its been at my dealer all week. I pick it up this morning. Their diagnosis is bad fuel and they claim to have consulted VW. Like I previously mentioned, absolutely no noise if the ambient temperature is above freezing or I use the block heater. When the noise is there it disappears in a couple minutes. So, I guess I make an appointment at another dealer today.
 

nord

Veteran Member
Joined
Mar 5, 2010
Location
Southern Tier NY
TDI
All turned back to VW. Now a 2017 Hundai Tuscon. Not a single squalk in 10k miles.
Bad fuel my arse! This is something far more serious. The TDI has a robust bottom end but this sounds too much like a rod bearing or wrist pin to ignore or pretend to be bad fuel.

I'm familiar with lifter noise. Anyone who has ever owned a slant six is. A drained lifter will "tap" until pumped up. Annoying yes, but not all that serious. This sound is much deeper methinks.

I'd say the same for an injector as far as noise and the apparent operation of the engine as you accelerated. I don't think you'll find the problem in the upper end.

If I were to lay money on a best guess I'd be looking at a failed wrist pin.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
There is no way it's bad fuel. How would bad fuel cause a sound on one cylinder and not all four?
 

tdiatlast

Top Post Dawg
Joined
Jan 21, 2009
Location
Fort Worth, Texas
TDI
2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
IMHO, do not drive your car. Phone another dealer (or two!) and ask to speak with the shop foreman or service director. Explain your situation, then send, or take them, the Youtube clip. (I'd want to be present when they actually listen to it)

Any technician with ears will hear the issue, regardless of whether or not the sound is present when the engine is fully warm. (I'll bet there IS something an attentive tech would hear!).

I've taken the liberty of forwarding the sound clip to an SA/friend that is very knowledgeable and has a real interest in cars. If he thinks it's mine, I trust he'll listen carefully and offer advice.
 

Salsaman06

Veteran Member
Joined
Dec 30, 2012
Location
Texas
TDI
2013 Passat TDI SEL (sold back to VWoA Dec 21, 2016)
I agree with what others have said. Something bad is wrong and sounds like something in the bottom end. My first impression is that this is a rod knock. It sounds like a rod bearing isn't getting any oil - or not getting enough - especially when you say it's worse on startup after sitting for a few days. Enough time for oil to drain out of the crankshaft passages thru the rod bearing clearance.
 
Last edited:

Rabert

Active member
Joined
Aug 19, 2014
Location
Fort Worth, TX
TDI
2012 Passat
Mine had a very similar sound. Only did it when the engine was cold. I could swear it was a rod/piston. Took it to the dealer, 4 weeks later they replaced an injector, all good now. I have a sound clip of you search for posts by my id. Th knock is not as prominent as yours but similar.
 

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
Mine had a very similar sound. Only did it when the engine was cold. I could swear it was a rod/piston. Took it to the dealer, 4 weeks later they replaced an injector, all good now. I have a sound clip of you search for posts by my id. Th knock is not as prominent as yours but similar.
I found your clip, that is EXACTLY what my car sounds like! My video sounds worse than it actually is.

http://s1287.photobucket.com/user/raberte/media/IMG_0919_zpsc7ce8d7f.mp4.html
 
Last edited:

Confused

Well-known member
Joined
Oct 1, 2014
Location
Mound, MN
TDI
2014 Passat TDI SEL Premium 2006 Jetta TDI
I say injector or oil. Are you sure the correct oil is in the car?
 

nord

Veteran Member
Joined
Mar 5, 2010
Location
Southern Tier NY
TDI
All turned back to VW. Now a 2017 Hundai Tuscon. Not a single squalk in 10k miles.
Let's put it this way... Something is causing a very deep knock or "thud". How it might be connected to temps is unknown and needs to be determined. The frequency of the knock tends to point to one cylinder which, in turn, leads toward the parts within that cylinder.

Since this knock seems to be related to engine rotation and seems to disappear as the engine warms, I'd have to agree that a faulty rod or pin would not "heal" itself. Usually I'd expect the opposite. Further, I'd somewhat expect that by now you'd have a new window in the block or at minimum some large metallic pieces in the oil pan. So we've got what appears a rotational knock in colder conditions which disappears as the engine warms. The engine hasn't shed any internal components and seems normal as far as operation and power.

Your valve train runs at half the speed of your crank so it rotates at just about seven times a second at an 800 rpm idle. Actually slow enough to count. Bottom end "knock" willl be at twice that rate for a bad component such as a rod or pin.

Once we determine the frequency of the knock we can begin to determine its cause. If directly related 1:1 with crankshaft speed, then it has to be the bottom end and has to be somewhere between the accessory pulley and the flywheel. Given that temps seem to be in play and that the engine is still in one piece I might begin to suspect a failed DMF if this be the case. "MIGHT", but I don't think so.

Should the frequency be 1:2 with reference to the crank speed, then you have a top end problem. Since dry lifters in my experience at worst only make an annoying "tap" until they pump up, I doubt a lifter problem. And since the knock subsides with temp and top end timing is hard set, I'm having a difficult time believing a mechanical problem with rotational components there. Of course it might be possible that you have a valve hanging in its guide and being returned by virtue of "help" from the associated piston. Since our valves are vertical in relation to the piston there's little chance of actually bending a valve but you'd certainly get a knock. Obviously this would indicate a serious problem between the valve and lifter. Very likely an immediate reason to pull the head.

Then the wildcard as far as I'm concerned... Injector problems. In theory it's possible for an injector to introduce fuel into the cylinder at some point well before it should. In this case and because your glow plug will be hot, it's possible to have ignition far before the normal timed event. This would certainly cause a deep knock as the piston would be driven in the reverse direction to engine rotation.

As I consider what I've shared I'm beginning to place the mechanical problems somewhat aside. If pre ignition or better said pre injection actually be the problem and associated with colder conditions, then I'd say glow plugs may be the key. They allow ignition without the heat of compression. As the engine gains heat, then compression takes over the ignition process. In your case a gross pre injection event would cause quite a rattle when cold but subside as things warmed. The timing and ignition of the affected cylinder would still be uncontrolled, but masked when hot. In other words similar to a runaway but not so due to the fact that fueling is still controlled.

So after hearing what I was sure was a rod knock... I think it is! Sort of anyway. Now I'm leaning toward a faulty injection event causing what those in the gasoline world think of as a pre ignition knock.

No matter though. A deep knock in any engine is cause for concern. It's not normal and it's a sign of a potentially serious issue. It can't be ignored.
 

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
Now I'm leaning toward a faulty injection event causing what those in the gasoline world think of as a pre ignition knock.
This is making a lot of sense to me. It does sound like ignition knock. Tomorrow, I will be making an appointment with another dealer to see if I can get somewhere with this.
 

Salsaman06

Veteran Member
Joined
Dec 30, 2012
Location
Texas
TDI
2013 Passat TDI SEL (sold back to VWoA Dec 21, 2016)
Well I will grant you that my experience with diesels and injector problems is nil. But that knock just seems too heavy and deep for a "pre-ignition" problem created by a malfunctioning injector. But hopefully, OP, your noise is not as bad as your video suggests as you said and its something less sinister like an injector or glow plug.


I don't see how pre-ignition can occur simply by a malfunctioning injector. Maybe someone can explain it to me. I *can* see it happening if say the glow plug is running hotter than it should be. Now that I think of it, as the engine warms up don't the glow plugs turn off?
 

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
The mic on my video is very "hot".
Rabert's video is much more typical of my noise http://s1287.photobucket.com/user/raberte/media/IMG_0919_zpsc7ce8d7f.mp4.html

My efforts now have to be to get a dealer and/or VW Canada to do something about it. Tomorrow I will contact VW Canada and another dealer. Today I sent an email to the service manager and owner of my current dealership about my dissatisfaction. It seemed because there was no error code, there was not attempt to repair. Based on Rabert's video sounding EXACTLY like my noise, and his remedy was replacement of a faulty injector, that's what I think my solution may be. My worry is the warming days now, as the noise only occurs below freezing. Starting with a new dealer, they may be unable to reproduce but I am going to try.
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
Did it Start knocking in 3rd gear? if that's the injector that the warm up cycle uses- the ECM will feed more fuel in at low temperatures, much more if not plugged in as that thing must reach a certain temperature at a given time. The diesel term for gasser like spark knock is "nailing" and can be caused by lots of reasons, ECM controlled over fueling for warmup with a bad or not great injector would cause this as if the spray pattern is off unburned diesel can hang around and build up until TDC and cause one heck of a noise. Its just like having one cylinder at full throttle without pilot injection and the rest happily firing at 1/4 throttle. Add the fact that the engine is barley spinning above 1,000 RPM a full throttle style "nailing" in the chamber will be very noticeable.
 
Last edited:

ranger1

Veteran Member
Joined
Feb 6, 2005
Location
SouthEast
TDI
NA
Based on the fact that it's temperature dependent, goes away as the engine warms up and never even occurs at all on a warm engine just seems to point to a fuel combustion issue. The rough running the longer the engine cold soaks points further to a fuel combustion issue worsened by cold weather.

Rod knock and broken DMF spring sounds generally don't disappear with warmer weather or engine warmup.

Whether a possible combustion knock is caused by a bad injector or a weak injector and a tank of out of spec low cetane fuel, I don't know. If this sound has persisted through more than a single tank full of fuel, it's likely not the fuel.

If you're down around a quarter tank of fuel, you could try double or quadruple dosing your fuel with PS Gray to raise the cetane and see if the noise level drops.

If it doesn't, I'd be asking a new dealership for a set of readings on your injector balance on a cold engine below the temp you mentioned. If you have a nailing injector that sounds that bad, it should show up in the injector fuel correction numbers or whatever VW calls them.
 

bboshart

Veteran Member
Joined
Jan 3, 2013
Location
Atwood, Ontario
TDI
2013 Passat TDI Highline 6M Sports Package
Well call me stupid, but my car went back to my same dealer for the fourth time for this issue. I thought I sufficiently escalated the situation with the management to get some proper attention and did not want to start over with another dealer. At last, a diagnosis of a bad injector. I don't get my car back until early next week to confirm.
 
Top