brief introduction to the nightmare...
One fateful day someone approached me and I purchased this really nice looking black touareg dirt cheap and thought it would be an easy fix. beautiful vehicle inside outwith navigation, back up cams, all leather was minty...looks like an audi q7 inside and I was impressed with its beauty ...
but was running rough. took valve covers off and it was full of thick sludge and left bank was not turning at all. Previous owners were just driving it with cheap conventional oil and engine was running on right bank only...removed engine and found left bank intake adjuster bolt loose and chain was freewheeling around the intake cam.not good! valves were bent. something major happened for that bolt to come loose.
decided to pull motor out and just rebuild this instead of buying a $2500 used motor and not knowing what I will encounter in the future. I would have put a used motor but these are very difficult to remove and requires all kinds of special tools, so I rather just rebuild this one with 98,000 miles, than to install a used motor and have to take it out again over stupid stuff.
I finished rebuilding the 2007 4.2L V8 engine code BAR
I have done many rebuilds before and this one was the hardest, tedious and labor intensive endeavors I have ever done. lots of sludge buildup and everything was completely disassembled, cleaned and serviced.
Parts were extremely expensive and hard to come by. Workshop Information is limited and generic. a simple oil filter had to be ordered because no one has it stocked locally in Florida. the BAR engine is rare around here. AXQ is common
Anyway, I hit a major road block with setting the timing chains correctly. I was so happy assembling the entire engine with all kinds of new internal bearings,parts and seals. basically ready to break in like a new motor. my last task after checking timing is to put the timing covers back on with new sealant and install this beast into my 4x4 beautiful Touareg. imagining my wife driving it with a big smile too.
after setting chains correctly and tightening all to spec, I was turning engine crank by hand clockwise and the cam shafts just lets valve springs slap around violently as I turn crank. after second rev the chains go off timing.
I am suspecting the pins inside these adjusters are slipping out of their bores. I have four barrel type cam adjusters on this engine. One on each cam shaft. they have locking pins inside. I suspect the pins are slipping out their bore holes because when I turn the crank by hand, the cams are slapping down loudly and you can hear clicking sounds inside them.
Anyway, searched forums and looks like these pins "wallow out" the holes they lock into and they recommend replacing them when servicing the chains.
Problem is that they cost $800 each and the cheapest was like $500 and ebay has a bunch of used ones for $170 but no info on what car it came out or how many miles. The photos don't show the inside disassembled.
I disassembled mine and it looks normal wear but when you turn the crank, it's a different story, they don't hold on to the cams and slip out. causing timing to go off.
so my question is....
theoretically, could I just modify these adjusters internally to stay in the locked position, assemble everything back?
The engine should still run fine I suspect? On low rpms, they stay locked. I heard if you accelerate then the solenoid activates, sending oil pressure into them and disengages the pins retarding the camshafts.
If they are permanently locked, then the oil won't do anything.
save myself a ton of money and just lock these adjusters down permanently.
Are adjusters absolutely necessary? what is their purpose really? I searched all up and down the web and no one has tried this alternative. I'm thinking it could work. Or maybe machine the surfaces of the sprocket plates to get rid of the worn area?
One fateful day someone approached me and I purchased this really nice looking black touareg dirt cheap and thought it would be an easy fix. beautiful vehicle inside outwith navigation, back up cams, all leather was minty...looks like an audi q7 inside and I was impressed with its beauty ...
but was running rough. took valve covers off and it was full of thick sludge and left bank was not turning at all. Previous owners were just driving it with cheap conventional oil and engine was running on right bank only...removed engine and found left bank intake adjuster bolt loose and chain was freewheeling around the intake cam.not good! valves were bent. something major happened for that bolt to come loose.
decided to pull motor out and just rebuild this instead of buying a $2500 used motor and not knowing what I will encounter in the future. I would have put a used motor but these are very difficult to remove and requires all kinds of special tools, so I rather just rebuild this one with 98,000 miles, than to install a used motor and have to take it out again over stupid stuff.
I finished rebuilding the 2007 4.2L V8 engine code BAR
I have done many rebuilds before and this one was the hardest, tedious and labor intensive endeavors I have ever done. lots of sludge buildup and everything was completely disassembled, cleaned and serviced.
Parts were extremely expensive and hard to come by. Workshop Information is limited and generic. a simple oil filter had to be ordered because no one has it stocked locally in Florida. the BAR engine is rare around here. AXQ is common
Anyway, I hit a major road block with setting the timing chains correctly. I was so happy assembling the entire engine with all kinds of new internal bearings,parts and seals. basically ready to break in like a new motor. my last task after checking timing is to put the timing covers back on with new sealant and install this beast into my 4x4 beautiful Touareg. imagining my wife driving it with a big smile too.
after setting chains correctly and tightening all to spec, I was turning engine crank by hand clockwise and the cam shafts just lets valve springs slap around violently as I turn crank. after second rev the chains go off timing.
I am suspecting the pins inside these adjusters are slipping out of their bores. I have four barrel type cam adjusters on this engine. One on each cam shaft. they have locking pins inside. I suspect the pins are slipping out their bore holes because when I turn the crank by hand, the cams are slapping down loudly and you can hear clicking sounds inside them.
Anyway, searched forums and looks like these pins "wallow out" the holes they lock into and they recommend replacing them when servicing the chains.
Problem is that they cost $800 each and the cheapest was like $500 and ebay has a bunch of used ones for $170 but no info on what car it came out or how many miles. The photos don't show the inside disassembled.
I disassembled mine and it looks normal wear but when you turn the crank, it's a different story, they don't hold on to the cams and slip out. causing timing to go off.
so my question is....
theoretically, could I just modify these adjusters internally to stay in the locked position, assemble everything back?
The engine should still run fine I suspect? On low rpms, they stay locked. I heard if you accelerate then the solenoid activates, sending oil pressure into them and disengages the pins retarding the camshafts.
If they are permanently locked, then the oil won't do anything.
save myself a ton of money and just lock these adjusters down permanently.
Are adjusters absolutely necessary? what is their purpose really? I searched all up and down the web and no one has tried this alternative. I'm thinking it could work. Or maybe machine the surfaces of the sprocket plates to get rid of the worn area?
