Just bought a 91 3000gt from a tow company, nice car but # 3 clyinder has no compression , does any one know how to to check if its the valves are bent or the problem is in the piston .

 

three things make an engine run,
1. compression
2. spark
3. fuel

Run a compression check on #3 first. 120 psi and up should be the range. probably much more because it's a high compression engine

If you can't run compression... and easy way it to remove the main coil lead, so the engine will not run... then turn the engine over and listen to it. If you have no compresison on one cylinder you will notice a skip in the cranking noise. ruur ruur ruur ahhh, ruurr ruur ruur.. something like that. (ok not the best example but I am trying!)

If that is over your knowledge.. just take it to a shop and let them diag it for you. go from there...

PS. let us know what you find!

 

I took it to a repair shop, it has a bent ex valve causing the problem , they want $900.00 to remove the head and fix the valve, Is the head really that hard to remove?

 

no but when a shop diagnoses a car it costs money so ur lookin at prolly an hour to diagnose the car, then u have all the parts that will need to be replaced, ur valve costs money, ur new gasket costs money and id imagine the shop gets around $100/ hr...it adds up very quickly

 

900.00 to do a valve job on a twin cam v6 engine? That's a good price for this day and age of repair. The guy I bought my 300gt from just had the timing belt replaced, and a tune up. Bill was $1,400.00 (tensioners and water pump is included with Timing belt replacement)

 

The $900 is just to remove and fix the one or two bent valves , which is all it really need to fix the problem , thou shops are hurting now and I have got prices for a lot less now.

 

Just had the head fixed, one new ex valve, $50.00, new head gasket $38.00 , paid a guy to fix ,mobil mechanic $150.00 to remove and replace , runs like new now.