engine problems

snakedaddy · Post by **snakedaddy** » Sun Aug 05, 2007 10:04 am

I have a VW based dune buggy and have a question. I overheated it and it started making knocking noises, loss of power, and started smoking with a grey color. I since changed the oil. Now when I drive it, it will run, sound great, and have good power for about 15 mins or until it gets hot, then I start hearing a "pinging" sound from the engine and have a slight loss of power and it starts to smoke.....Does anyone have an idea of what that could be.

couion · Post by **couion** » Sun Aug 05, 2007 7:50 pm

Either way its not good news. A VW engine is what's known as a bi-metal engine. The heads and case are aluminum and the cylinders are cast iron.
These have a tendancy to heat and cool at different rates which if over heated is not good news. From the description you are giving I would look at the pistons which are also aluminum sounds to me like maybe a piston ring is seized to the piston. This would cause it to act and respond the way you described. The smoke is likely oil slipping past the rings and the noise may be the piston slapping against the cylinder wall.
Good Luck Hope this helps Scott

thatguy · Post by **thatguy** » Wed Aug 08, 2007 12:14 pm

Just went through a similar thing with my 1600 dual port...bearing went south after a ring popped in the case.

I had ring and bearing parts strewn all throughout the case - not good. It just got to hot here in the Houston heat and the pistons didn't coll off quick enough(what my VW mech-head told me anyway). Had to do a full-on case-splitting rebuild. No more pinging, smoke, or loss o' power now though. A lot of work for me, but at least the rebuild part was fun.

snakedaddy · Post by **snakedaddy** » Fri Aug 10, 2007 10:46 am

Thanks for the responses, I guess I pretty much know I was screwed, I was planning on driving it until it died. That is before I read the last post! Oh well I guess I will just drive it until she blows anyways, then just drop a new engine in her. I better make sure the cell phone and the AAA services are in good order.

thatguy · Post by **thatguy** » Sat Aug 11, 2007 8:36 am

The rebuild is not bad at all...provided you can take you tine and do it right. It took me a Friday evening to properly pull all the wiring and such - labeling as I went of course

- and then drop the motor. 8:00 am Saturday hit the ground running. Took about 6 hours to do a strip the carcass..er, motor

Then after a lunch/nap break I split the case...not for the faint of heart I must say! But, once the deed was done, it was not as bad as I thought. Pulled everything out, clean it good, and put it back in. Spent the last couple of hours putting the thing back together and at about 9:30pm I got to go to bed.

Sunday after church - spent 3-4 hours stabbing it back in and reattaching the labeled stuff, and away I went.

Not so bad if'n you take your time.

And it is MUCH cheaper than replacing the motor.