[albertr]

Great project!

Rusted exhaust manifolds was a problem on my 2001 EVC too. When was doing chains past winter, I was not able to remove them and had to move engine forward with downpipe still connected. Luckly, there was sufficient clearance to do that.

As far as rusting on the back side of the crankcase, my original 2001 AXK wasn't that bad. There was some rust, but nothing nearly as dramatic as seen on your pictures! There must be something leaking there in your engine that caused such severe rusting.

Why the plug was blown off in your "good" BDF? With cracked oil pan, I would be very cautious to inspect all internals to make sure it was not ran dry by his previous owner…

-albertr

[Itsamoto]

Great project!

Rusted exhaust manifolds was a problem on my 2001 EVC too. When was doing chains past winter, I was not able to remove them and had to move engine forward with downpipe still connected. Luckly, there was sufficient clearance to do that.

As far as rusting on the back side of the crankcase, my original 2001 AXK wasn't that bad. There was some rust, but nothing nearly as dramatic as seen on your pictures! There must be something leaking there in your engine that caused such severe rusting.

Why the plug was blown off in your "good" BDF? With cracked oil pan, I would be very cautious to inspect all internals to make sure it was not ran dry by his previous owner…

-albertr

Thanks Albertr -- I was really surprised as well when I saw the condition on the back of the block. The front had some bubbling paint - but nowhere nere what was on the back.


The Bad AXK -- bubbling paint

As for the missing plug -- this enters the "air port"  --  further along the same channel in the head where to which the combi-valve feeds. I'm hoping that it has just fallen/blown out - rather than getting sucked in. I have no clue why this could or would have happened. When an engine is installed -- this is somewhat out of sight and covered up by the exhaust manifold heat shield. Neither of the other two engines have this port "opened" on purpose - so I don't think its intentional.

I do have some concerns with the engine having run dry -- but I am not sure what to look for. The history of the donor Jetta was that it ran up an ice bank in the middle of winter (i.e. -40C). The force of impact broke the driver side axle and control arm, punctured the transmission case and bell housing, and ripped that gash in the oil pan. Both air bags deployed -- but I don't know if that triggers the engine to shut off. So a good bet that the car may have been run afterwards to warm the occupants for probably 45-60min. Not sure what to look for - but it turns over by hand very smooth - and the crank case has no evidence of oil starvation. Any suggestions?

[albertr]

Good question... I'm not experienced in engine rebuilds, so not really sure. Maybe pull out oil pan and valve cover and look for any metal shavings or signs of metal particles in oil and on internal parts? Also, mesh net filter screen on oil pump intake,  inspect it for any deposits? There's also some third party companies who can do chemical analysis of used motor oil, maybe send them a sample?

-albertr

[Itsamoto]

The difference in oil residue and condition is quite noticeable between the good BDF and Lucille's original AXF. I'm taking notes on this, and thought it might be interesting to share the findings from the 3 engines. If anything, it serves as good example of synthetic versus conventional oil.

Valve train/Cylinder head


Good BDF


Bad AXF


Ugly BDF

Crankcase


Good BDF


Bad AXF

Valve Cover

From L-R: Good BDF, Bad AXF, Ugly BDF

Here's a close up of the important detail -- found in the oil vapour filter mesh. Note that the filter on the AXF was so clogged and coked up that I had to adjust the exposure to get any sort of comparison.


Good BDF


Bad AXF

Lower Chain Tensioner


Good BDF


Bad AXF

Timing Chain Cover


From L-R: Good BDF, Bad AXF, Ugly BDF

[Itsamoto]

Lucille's oil system components were totally coated in sludge and coke -- I've owned her for 20k miles of pure synthetic oil changed every 7k. Evidently, the idea that running synthetic can help clean sludge out is not evident here. 

More....

Oil Pan and Pump


From L-R: Good BDF, Bad AXF, Ugly BDF


Good BDF: Note the crack/hole in the pan (bottom right) and aluminum chips (~centre).


Bad AXF


Ugly BDF: Looks good in comparison.


Ugly BDF: Metal fragments!

Oil Pump


Good BDF

This also nicely shows the difference in reach between the BDF and AXF oil pumps. FYI: there is a 3rd, shallower pump style used on some 3.2 VR6 -- about 0.75" shallower than the BDF's. 


Bad AXF


Ugly BDF


Ugly BDF -- Crunch!

[albertr]

Great pictures! It's good to have multiple engines, make comparing and swapping parts much easier

However, my 2001 AXK had even worse sludge issue comparing to your "bad" AXK, so your synthetic oil might have done some cleaning job afterall ;-)

Below please see some horror pics of mine. After chain replacement it still continues to run fine (I keep my fingers crossed  ). Somebody (Cole perhaps?) was tossing idea that AXK sludge issues might be related to unusual mounting position on EuroVan (engine is tilted forward) which could attribute to oil starvation.










-albertr

[kjeff]

Don't read too much into sludge. It's not always a lack of maintenance that cause an engine to sludge up and a clean engine doesn't always mean it was well taken care of (matter of fact a higher mileage engine with a lack of sludge usually means somebody poured some miracle in a can cleaner in it). Higher operating temperatures stop and go driving, lots of short trips add to sludge build up every bit as fast as not changing the oil regularly.

Sludge is created by any number of factors, todays engines tend to be worse because of the higher compression ratios we're seeing and the higher oil temps both of which lead to faster break down of the oil.

if you're staying on top of oil changes, keeping it topped off, making sure the car is always running properly there's really not a lot more you can do to avoid sludge. It happens

Edit: I want to add another cause too many short trips where the engine never really gets up to operating temp. This allows moisture build up in the oil, creates foaming which in turn creates sludge

[Itsamoto]

Great pictures! It's good to have multiple engines, make comparing and swapping parts much easier

However, my 2001 AXK had even worse sludge issue comparing to your "bad" AXK, so your synthetic oil might have done some cleaning job afterall ;-)

Below please see some horror pics of mine. After chain replacement it still continues to run fine (I keep my fingers crossed  ). Somebody (Cole perhaps?) was tossing idea that AXK sludge issues might be related to unusual mounting position on EuroVan (engine is tilted forward) which could attribute to oil starvation.

-albertr

Yes your engine looked worse. How many miles what that at?

Having multiple engines to work with helps a lot. The AXK is actually just "ugly" with rust and the sludge. The second BDF is totally shot -- and basically I got it for (1) the crack pipe and (2) to just learn from messing around with it.

I don't know if the angle has anything to do with the sludging - I wouldn't rule it out. I do know that from all the VW's I've owned from the era in which the van was (circa 2002) -- that none of them were specified to use synthetic oil (when they probably should have). So, with my 2002 2.0 Jetta (I'm the original owner) - I switched to synthetic after 6 years of regular oil - and then switched back to conventional after it developed an oil leak. All good on that front. My 1.8t on the other hand - needs synthetic or it will coke up fast due to the heat of the turbo.

And I agree with Kjeff -- that regular oil changes before the oil breaks down probably does a lot to circumvent any buildups. But from here on out on the van's  VR6 - its got to be synthetic from now on. 
 

[Itsamoto]

Here is a quick example of a critical oil passage -- and it has to do with one of our favourite subjects -- timing chain!

So here you can see the upper timing chain cover --where there is a small oil passage that feeds the chain tensioner bolt.

Upper Timing Chain Cover


And here on the tension bolt - is the oil inlet which not only takes in oil to lubricate the internal spring - but the oil is also needed to pressurize the tensioner to its final and correct tension! When this is installed correctly - the oil ports align. If this starts to clog up and restricted with sludge, then it seems very plausible that the chain is no longer tensioned correctly - thereby increasing the wear on timing chain components.

Timing Chain Tensioner

[albertr]

Yes your engine looked worse. How many miles what that at?

Having multiple engines to work with helps a lot. The AXK is actually just "ugly" with rust and the sludge. The second BDF is totally shot -- and basically I got it for (1) the crack pipe and (2) to just learn from messing around with it.

I don't know if the angle has anything to do with the sludging - I wouldn't rule it out. I do know that from all the VW's I've owned from the era in which the van was (circa 2002) -- that none of them were specified to use synthetic oil (when they probably should have). So, with my 2002 2.0 Jetta (I'm the original owner) - I switched to synthetic after 6 years of regular oil - and then switched back to conventional after it developed an oil leak. All good on that front. My 1.8t on the other hand - needs synthetic or it will coke up fast due to the heat of the turbo.

And I agree with Kjeff -- that regular oil changes before the oil breaks down probably does a lot to circumvent any buildups. But from here on out on the van's  VR6 - its got to be synthetic from now on.

My AXK had 147K miles on it which were put by his previous owner. He used to go to Pep Boy's to do his oil changes  I guess that contributed to sludge issue somewhat... 

-albertr

[Itsamoto]

My AXK had 147K miles on it which were put by his previous owner. He used to go to Pep Boy's to do his oil changes  I guess that contributed to sludge issue somewhat... 

-albertr

I was reading up through the 24v Timing Chain thread that Cole started and I was re-reading through your contributions there. That was awesome work, if not incredibly thorough. Makes me grateful that I have the engine out to do this. 

[Cole]

I was reading up through the 24v Timing Chain thread that Cole started and I was re-reading through your contributions there. That was awesome work, if not incredibly thorough. Makes me grateful that I have the engine out to do this. 

You'll also notice in that thread how sludged up that 24v AXK was with 152k on it and a lifetime of synthetic from the original owner.

[Itsamoto]

You'll also notice in that thread how sludged up that 24v AXK was with 152k on it and a lifetime of synthetic from the original owner.

Interesting. Do you think this is related to the tilt of the engine then --- building up more heat in areas or not getting properly supplied with oil? Or should we be looking at an external oil cooler?

One thing I noticed that is a bit different between the BDFs and the AXF - is the routing of the coolant lines. The AXF closes off using the center port off the block, where as the BDF's used that. The routing and positioning of the after run coolant pump is a bit different too. We need some thermal imaging here!

One other factor to consider, is the type/model of car that these engines were available in. 24v-vr6 BDF's were in GTI's and GLI's -- basically the top of the line MK4 Golf/Jetta. Perhaps new owners of these cars were more in "tune" with the needs/demands/maintenance of the engine than the average Eurovan owner was. Getting a 24v VR6 was an option/choice to those Mk4 owners -- where as with the Eurovan owner, it was their only choice. 

[Cole]

I'm curious about the tilt of the engine too.

That thread has stimulated at least a dozen people calling me to ask about that specific topic.

I'm no oil expert so all I can do is speculate on the causes. But there does seem to be a trend with the Eurovans not seen in the cars.

The Eurovan, especially the camper versions were/are expensive. So I'd imagine most people took care of them. The original owner of my black van from the original thread took great care of it. Yet it sludged.

I've noticed that the fans on a Eurovan run far more than any other car. So I image getting rid of the heat is a large prt of the issue. Might explain the flaking paint on the engine blocks (the one I removed was also flaked)

[Itsamoto]

I've noticed that the fans on a Eurovan run far more than any other car. So I image getting rid of the heat is a large prt of the issue. Might explain the flaking paint on the engine blocks (the one I removed was also flaked)

The downpipes in the Eurovan certainly run adjacent/parallel to the engine for much longer than the BDFs -- where the downpipes  slant away (if that make sense) and have heat wrap around them. That would certainly account for some extra heat at the back the engine.

I will pursue shielding up the van's with a similar wrap.