Cam Wear and Mileage

[1340]

I read a thread the other day where the OP talked about
a gradual mileage decline and contributed it to cam wear that
he found. I have a similar situation. Car runs fine, no apparent problem,
but mileage has been declining for about a year. I'm down 4-5 mpg.
Can cam wear cause a loss of mileage?
Thanks.

 

[Krytie TV]

Indeed it can. It can rear it's head anywhere from 75k miles to 200k miles.

 

[Max Attitude]

Make sure you check it thoroughly. Our cam was really bad and the motor actually ended up dropping a valve. Its a lot cheaper to replace the cam than rebuild/replace the engine. We bought our car with the cam in bad shape ( not knowing it). I thought the turbo actuator was bad...has similar symptoms.

BTW, the Cummins swap Dakota sounds cool.

 

[usernamehere]

I picked up a 2006 Jetta 1.9 TDI 293,000. Has cam wear, looks like it is the original cam. One lifter was trashed and has a deep groove worn in it from the cam seal. Sent the cam to Crower cams San Diego CA. to be reconditioned. I will report back on service and cost. I did not take before pics because I wanted to get it shipped out today. I will post pics when I get it back.

 

[Max Attitude]

usernamehere- Not saying it wasn't...but that cam could have been replaced a couple times by that mileage. Some have had theirs go out before 100k.

 

[Krytie TV]

usernamehere- Not saying it wasn't...but that cam could have been replaced a couple times by that mileage. Some have had theirs go out before 100k.

I have a suspicion that he is referring to km, as in 175k miles. Might be wrong but I believe I remember it from another thread.

 

[Max Attitude]

That would make more sense. Mine went 193,000 miles

 

[usernamehere]

It's Miles! I just can't believe that it had a cam replacement before I got it.
It still had the paint marks on the bolts from the factory. The builder/operator marks it after it has been torqued. Common manufacturing practice. The groove worn where the oil seal rides was about a 1/16 deep. I believe that it is a oiling/bearing problem that causes this. I think that after I fix it I will inspect and replace the bearings every timing belt. The way the bearings are worn may cause this.

 

[Henrick]

The groove you are referring to is something what should be there. It's a special groove for the cam seal to ride in. If you take a brand new OEM cam you will find that groove there too!

 

[SVTWEB]

Having watched this phenomenon for the last five years, the data suggests that Owners who drive long distances on a daily basis see their cams fail at much higher mileage numbers than those who only ride short distances. This would lead me to hypothesize that a majority of the cam wear occurs during the startup/warmup period. My first (and only thus far) cam failed at 206,000. I have seen 2 cars with less than 60K on them have a failed cam.

It is feasible that the vehicle with 293,000 miles could be on the original cam. So the long of the short is the Start/Stop cycles are the detriment to the design, not the mileage.

 

[Henrick]

I think it's the opposite. High speed long highway drive at elevated oil and ambient temps is what hurts the followers and the cam.

 

[usernamehere]

The groove you are referring to is something what should be there. It's a special groove for the cam seal to ride in. If you take a brand new OEM cam you will find that groove there too!

Had dealer pull one, no groove on new BRM cam. Can anyone else support this claim?

 

[gopher]

For what its worth, my 2005.5 TDI DSG went 341300 miles on the original cam before failure; 505.1 oil changes every 2500-3600 miles, conservative driving habits, mainly highway driving at 68mph. A VW guru installed a cam from Frank resulting in mpg increase of about 3mpg. After 11,000 miles on the new cam the engine still runs like new .

 

[Bob_Fout]

Some kind of joke? Oil changes around 3K miles?

 

[gopher]

cam wear and mileage

I believe that frequent oil changes, with manufacturer specified oil, along with careful engine break in and conservative driving habits are key to long engine life. My VW guru in Jacksonville, Fl. told me that he never heard of any 2005.5 VW Jetta TDI getting 341000 miles on the original cam so my frequent oil changes cant be a "joke". Perhaps others have duplicated this and I would like to know how they cared for their cars. Incidentally, I had a 1986 Mercedes 300D (euro model) that had 527,000 miles with a perfectly functioning engine that was never repaired and was not consuming any oil when I had to dispose of it when the frame cracked (broken flex disc on the axle caused this) and I had changed the oil every 2500 miles using Mobil 1 on this vehicle. I suspect that others achieving very high mileage without engine repair are also doing frequent oil changes. Living in Florida with the high number of days with over 90 degree F temps also can result in oil quality deterioration. Lets hear from other very high mileage drivers regarding their frequency of oil change.

 

[usernamehere]

I believe that frequent oil changes, with manufacturer specified oil, along with careful engine break in and conservative driving habits are key to long engine life. My VW guru in Jacksonville, Fl. told me that he never heard of any 2005.5 VW Jetta TDI getting 341000 miles on the original cam so my frequent oil changes cant be a "joke". Perhaps others have duplicated this and I would like to know how they cared for their cars. Incidentally, I had a 1986 Mercedes 300D (euro model) that had 527,000 miles with a perfectly functioning engine that was never repaired and was not consuming any oil when I had to dispose of it when the frame cracked (broken flex disc on the axle caused this) and I had changed the oil every 2500 miles using Mobil 1 on this vehicle. I suspect that others achieving very high mileage without engine repair are also doing frequent oil changes. Living in Florida with the high number of days with over 90 degree F temps also can result in oil quality deterioration. Lets hear from other very high mileage drivers regarding their frequency of oil change.

I bought mine with 293,387. Cam appears original. Has a bottle of Mobile 0w30 in the trunk. First cam lobe and lifter had significant wear. I was thinking with this high mileage, should I replace the oil pump. Have you replaced yours? I plan on running Rotella T6. I am also adding oil pressure gauge.

 

[Henrick]

3k miles is overkill. Go 7k miles in extreme conditions (city driving, cold starts) and 9k miles with mainly highway driving or longer trips. That Mobil 1 0w30 wasn't 506.01 certified, I'm sure.

 

[James & Son]

I bought mine with 293,387. Cam appears original. Has a bottle of Mobile 0w30 in the trunk. First cam lobe and lifter had significant wear. I was thinking with this high mileage, should I replace the oil pump. Have you replaced yours? I plan on running Rotella T6. I am also adding oil pressure gauge.

A bunch of newbies here and we're back to the same old same old this and that causes cam wear. Yes there is a single problem as far as I am concerned and it is not a design problem( in the classic sense of a cam problem) or oil problem that I can see other than the cam bearings do wear out and according to Bently should be replaced at a certain wear clearance, but copper showing is just as good an indicator.

The cam is being pushed up and pushed down every cycle and if the followers get caught in the squeeze and the cam is ground rough on the closed dwell of the cam this is where you get your wear out in a 100,000 miles( the lobe does not matter if it ground rough as it will break in). yes the usual million other environmental conditions can delay or speed the issue up.

Edit, forgot, usernamehere, besides the oil pump chain, you could even consider valve springs and seals then you could check your turbo end play etc....

 

[V-Rod]

So the long of the short is the Start/Stop cycles are the detriment to the design, not the mileage.

I agree ^^^ But I think when it comes to this particular motor I think high RPM's are another factor.

My 06 Jetta just turned over 170,000 miles. Engine has no cam problems yet. I change my oil every 10,000 miles and I change the oil filter every 20,000 I use a 5-40 505 oil. Average 1 way drive is 60 miles.

Car drives in some extreme conditions, hottest being 105 coldest so far being -44F plus gravel roads.

 

[Henrick]

Is there any reason you skip the oil filter at every other oil change?

 

[James & Son]

Originally Posted by SVTWEB
So the long of the short is the Start/Stop cycles are the detriment to the design, not the mileage.

V-Rod
I agree ^^^ But I think when it comes to this particular motor I think high RPM's are another factor.

My 06 Jetta just turned over 170,000 miles. Engine has no cam problems yet. I change my oil every 10,000 miles and I change the oil filter every 20,000 I use a 5-40 505 oil. Average 1 way drive is 60 miles.

Car drives in some extreme conditions, hottest being 105 coldest so far being -44F plus gravel roads.

Well lets see in 2006/2007 the first cam wear shows up on a BRM after 39000 miles. It was analysed to death and it wasn't cam bearing wear as first predicted by both frank and eddif. Prior to this, cam wear was showing up on some Passats and Bew. After having to torch out siezed followers Frank declares its not enough oil and the oil passages are being block by cam bearing wear and the followers are not getting enough oil. This is where Franks cam bearing mods were developed.

Anyways the used oil analysis would soon have picked up on the start stop theory as this analysis has been well documented for BRM.

How about taking another look at my theory. Lets see if the valve spring forces push the cam up and the hydraulic followers on the cylinders that are on compression and ignition take up the clearance as they are designed to do.

Then what happens to those followers when the injector fires at there usual 10,000/14000 psi when cruising at 1800/2300 rpm. The valves are held closed by compression and igniting and expanding gasses as well as springs.

No the bearings are not taking the load the followers are!
I have the pictures to prove it. Now does this happen all the time, enough that a conservative driver like myself found this issue starting at 35000 miles.

I have the pictures to show pickup and galling on the closed dwell portion of the cam which coincides exactly with the injector firing and the followers on #1 exhaust and #2 exhaust had the centers ripped out. Yes hardened steel ripped out by galling. The cam lobes were fine but there was pickup on the closed portion of the cam dwell.

Like I said if you have a coarsely ground cam the closed dwell portion does not break in to allow the normal squeeze lube film to develope that a smooth surface would. The injection happens in 2 to 3 millisecs. This contact of surfaces actually shears the black coating away over time and if the cam is not smooth it will destroy the center dot of the follower( this has nothing to do with the lobe). Thus the term follower center dot wear which eddif determined was caused by shock forces. I now have pictures to prove it.

If I was buying a cam I would make sure to the seller ahead of time that if the closed dwell was not smooth I would be returning the cam for a full refund.

Now I expect you guys to read this and comment. I have commented on your theory so I expect a reply.

 

[SVTWEB]

J&S.. Some very valid points. I really didn't follow many of the cam wear posts that early because my can had been unaffected by the issue. But you do bring some extremely valuable information to the table that supports both theories.

When the first BRM was showing signs of wear in 2006/2007 with 39K on it, my BRM already had 70K on it. In early 2008 I did my first timing belt at 100K. Once again there was no checking of the cam because it wasn't on my radar screen. Oil changes were every 10K (as I change every filter on the car at 10K also). in 2012 I did my second timing belt at 200K, to my detriment I didn't check the cam at the time. My cam failed about 10 miles from home driving on the highway at 65MPH with 206K miles. It was a subtle failure of the #1 exhaust lifter with a small crack that wouldn't allow the oil-pressure to pump up the lifter. The car now has 230K on it and is going strong with the exception of the worthless EGR cooler/Automated BW exhaust blow-by device. (Soon to go bye-bye). Since day one the car has always been used on long-haul commuting. 65-70MPH for 1 hour, 1-way each day. Little to no city driving ever. when I get to the 300K mark at the end of 2014 I will make sure that I check the cam.

So with this being said, my car runs at higher RPM's, for longer periods of time. Maybe, the Higher oil pressures with the higher RPM's and the fact that the engine is maintaining a steady RPM/TEMP makes the cam wear issue less prevalent than those drivers who have a short commute and are stopping and starting.

I am sure that I am not the only BRM out there that had a cam go over 200K, and their car is a long-haul workhorse. What would be valuable would be just the basic data of Vehicle year, Mileage when cam failed and total mileage on vehicle.

 

[LuvDaDiesel]

2006 - replaced cam at 235,000. Daily commute is now 150 miles round trip for last two years. Previously was 70.

 

[SVTWEB]

2006 - replaced cam at 235,000. Daily commute is now 150 miles round trip for last two years. Previously was 70.

Another valid data point that we "Long Haulers" have fewer cam issues than the "tag-alongs".......

 

[James & Son]

Another valid data point that we "Long Haulers" have fewer cam issues than the "tag-alongs".......

The cars I have owned I have kept them well past there prime and design life. Most manufactures make sure the motor and transmissions never let you down or put you on the side of the road and the cars I have owned have never let me down in that way.

But the VW 2005/2006 is a car that has quality control issues, not all cars but a lot. It is not unknown for some people to have over 10,000 in repair bills and the cars have not reached what one might consider a design cycle life for the parts and the cars are under 6 years old.

As far as the cam goes there is nothing wrong with the design. In fact VW went to great lengths to get it right and it should last a long time. The car starts in less than 90 degrees of first crank. At idle the cam lobe is well into EHD lubrication at 1.5 meters per sec. There is absolutely no reason for the cam to wear out whether you are high miles or low miles driver. the spring force is only 147 lbs on the lobe. The lobe width is equal to the old chevy V-8 cast iron shafts that had slightly radiused lobe profiles.

The lobe does seem to edge load but proper break in and black followers should have solved this problem.

Like I said if the cam is coarsely ground in the closed dwell zone, you are ukered. Since colt and franks cams are reprofiled finish grinds there should be less of a problem in the future with these. I would buy OEM only if I was guaranteed a smooth finish grind by the seller.

A coarse grind cam on a any car including the PD, the lobe will still break in( with lots of Zddp) fairly quickly because there is more slippage than rotation, but on the closed dwell of the cam the follower gets mostly rotation from the cam and does not have high forces here and does not break in as quickly. The PD can have high forces here and this is because the follower is receiving the injection forces instead of the cam bearings, probably at certain times and not all the time( high rpm for sure). I have the pictures to prove it.

What I am saying is a coarse grind in the closed dwell leads to a certain amount of follower scuffing. The followers can self heal if the scuffing is not severe and long drive cycles may or may not have anything to do with this scuffing and healing. It could be just another quality control problem that is taking a long time to go away( a short drive cycle may prevent total healing). The better finish on the cams that we are now using( assuming this is the case) should lead to fewer issues for everyone.

 

[usernamehere]

Had dealer pull one, no groove on new BRM cam. Can anyone else support this claim?

Henrick, You are right! Cam shop said it appears to be machined. Maybe VW changed it mid year or something. Now I need to find the right seal to use.

 

[James & Son]

Henrick, You are right! Cam shop said it appears to be machined. Maybe VW changed it mid year or something. Now I need to find the right seal to use.

I have an OEM cam replaced under warranty by the dealer in 2009. It now has about 65000 miles on it and it is showing some groove wear under the buna-n cam seal, that i could not replace the seal with the new teflon seal in my Diesel Geek timing belt kit.

I would have crower reweld this to but other wise check the old seal to a stock new seal and i bet they are the same. Unfortunately just a worn groove. Mine doesn't leak but I am no wear near 300,000! This groove alone proves you have a lot of miles on the cam.

Edit: my groove is only about .010 to .015 deep but I am pretty sure the seal did it as it imperative that i very carefully position it as there is a definite
wear spot that it fits into.

 

[usernamehere]

I have an OEM cam replaced under warranty by the dealer in 2009. It now has about 65000 miles on it and it is showing some groove wear under the buna-n cam seal, that i could not replace the seal with the new teflon seal in my Diesel Geek timing belt kit.

I would have crower reweld this to but other wise check the old seal to a stock new seal and i bet they are the same. Unfortunately just a worn groove. Mine doesn't leak but I am no wear near 300,000! This groove alone proves you have a lot of miles on the cam.

Edit: my groove is only about .010 to .015 deep but I am pretty sure the seal did it as it imperative that i very carefully position it as there is a definite
wear spot that it fits into.

James, it's already been shipped back to me. Should get it soon. I asked them to weld it up and they said it should be there. The seal on it didn't leak. There were 3 seals listed for it when I looked it up.

 

[JettaJack]

My 05.5 only went 140000 before cam wear almost toasted the engine. 10k oil changes (like clockwork) with total!
First noted at 60000 by TdiRacing.