My Jetta has been making a knocking sound which my mechanic has determined is caused by the cam lobes hitting something they shouldn’t which has scratched them up. He has given me options to consider:
Sell the car and/or trade-in and buy a new one
Replace the engine either used ($2800) or remanufactured ($4200)
Repair the engine (replace rings, main and rod bearings, crankshaft, camshaft, burnish cylinders, grind valves and tune engine - $4100)
the problem with repairing is that the parts are apparently not available anywhere nationwide currently; will take up to 2 months to come in.
I’m not sure if I should even be driving the car at the moment, and I’m not sure as to the best choice. Car has 124,000 miles, I am the original owner and have always kept up on the maintenance. Financially it’s not a good time to buy a new car. Any insights or things to consider are appreciated. My mechanic also said the camlobes will eventually break and completely ruining the engine forcing me to get a replacement.
@mleich he said he cleaned everything up as best he could and put it back together. I take that to mean there were some shavings or something. The actually sounds pretty good at the moment, better than before. When you say “explodes”, how catastrophic are we talking? Literal fire or the engine loses power and dies?
IF and only IF this car is in good shape otherwise, I would look on some of the VW user forums for a good set of used cams and lifters (must but them in a set) and throw them in. I will tell you the VR6 is a VERY expencive motor to replace, and not the eaiest thing to work on, so even labor to replace the cams is going to cost you some $$$… Good luck !!
Cam lobe problems are usually caused by an irregular oil change regimen in which contaminants in old oil manage to wear through the hard coating of the cam lobes or too much slop in the valve lash. The latter meaning weak lifters due to oil sludging or poor circulation. This usually falls back onto irregular oil changes.
It sounds to me like the engine is pematurely worn out but I couldn’t see going the burnishing the cylinders route as it’s referred to. That sounds like one of those engine-in-car ring jobs which may or may not turn out to be successful. Much would depend on the condition of the cylinders and crankshaft journals and how they measure out; assuming they would even be measured with micrometers.
A used engine would be the best route but you also walk into a minefield because you often never really know what shape that used motor is in until it starts and runs.
I’d just keep driving it until the engine fails, meanwhile saving up for a replacement vehicle. Do not have more work done on the existing engine, it’s damage is probably to lots more than the camshafts. Only other reasonable alternative is like ok4450 says, a used engine, but hard to tell how good it is. $4,000+ for a rebuilt engine would be more than it’s worth, to me.
What you should find out is if its just one cylinder head that has the problem, ir if its more than one.
If its just one, I would recommend looking for a new cylinder head and components, and have your mechanic replace just them.
I don’t understand why your mechanic wants to replace the whole engine if its just a camshaft/valve train issue.
Engine loses power, check engine light comes on, misfire, rough running. No actual explosions or fire. The engine’s death is a whimper, not a bang. You should be able to limp home no problem. It could take days, it could be months.
The reason for the engine rebuild or replacement might be due to irregular oil changes. If the valve train is damaged because of the oil change regimen it’s quite likely the entire motor is suffering.
You could continue to drive the car as is for months, or even years, as mentioned. The odds of a cam lobe breaking off is very, very slim. Odds are what will happen is that it may go flat over time. This will start off as a tick that eventually could turn into a knock. You should dhave plenty of warning.
However, it’s not a car I would take on a cross-country trip.
YIKES…Just HEARING this issue makes me cringe…Not sure if you guys are familiar with VW’s NAAROW angle VR6 engine or not…BUT OH BOOOOYEEE…Ever see a cylinder head from one of those VR6’s? Its a MARVEL of engineering but God help you if you have issues…That engine has ONE cylinder head that covers ALL the 6 cylinders despite being a “V6”
I hate to hear the issue you are describing but honestly a “GOOD” mechanic will know how to go about fixing it…YOu need to have the cam journals machined and inserted with different plain bearings…that MAY not be a possibility tho on that engine…Hmmm…but it should be… I guess what they would do is swap heads and be done with it…BUT the cost of that HEAD!..UGH…