2001 vw passat mechanic doesnt know why engine loops wont stay running
ok here is whats going on. my first Passat 2001 2.8 v6. bought it knowing it had overheating problem. in excellent condition, ran great, what a great deal I thought. well I drove it 1 day, that was before xmas. this is not my first time working on a car. I removed everything needed to replace waterpump. didn't remove the crank pulley and timing belt left that on so I didn't mess with timing and careful not to move camshafts. put it all back together. it wouldn't start. during the work I removed battery (didn't know not to remove battery)it was out of car for about 2 weeks as I worked in spare time. when I had it back together at one point I set off alarm system (the original radio has been replaced). I don't have the remote control key only the chip key. used obdII scanner and the only thing that came up was throttle position sensor and mass air flow well I eventually got a chiltons vw/audi manual. read it went back and re did the timing placement (which came out correct on marks that I had made) and made sure elec plugs for everything else was correctly done, including somethings that I didn't even touch that were not correctly in place. from there I sent it to a vw/audi mech to have engine parameters reinstalled. after a week he said the ECM info would only give throttle position sensor low & high codes. that ECM would not reset so he could set parameters. he could erase codes but that's it. also 5 & 6 cyl were at 82 and 90 psi respectively. he didn't know what was wrong with it and had spent 10-12 hours on car. installed a new battery as well. I have checked with compression tester myself and got same readings. 1-4 cyl are at 120 psi. from past engines I know the engine should start and run, yet only will start for 5-10 seconds looping and die. I checked 4,5 & 6 cyl spark wires and only have 2000 ohms, wires are cracked, and one is badly corroded at the ignition coil side. I know that wires need to be replaced. just could that be the reason it wont start. frustrated after buying car and cant get it running.
Hmmm you might need to get your throttle body reprogramed... when you disconnect the battery the throttle on these vehicles tend to loose the position they are suppose to be on
ok. is it possible to connect my scan tool to another Passat same year etc... and download the info from that one on scanner and then upload the parameters to my Passat. trying to avoid even more spending than I already have lost and losing as well. I have decided to pull heads and replace gaskets. used a camera scope and looked inside through park plug hole and it clearly looks like blown head gasket. more so is that #5 and 6 both have low compression. cant get them to go above 80 psi after about 5-6 revs of engine. 1-4 cyl easily hit 120 psi by 2 rev. plus there are no marks on valves or piston head to indicate a collision.
Try a wet compression test. This should help you determine if you have bad piston rings, valve or cylinder wall.. take spark plug off your cylinder with low compression add oil, put your compression tester back on. If your compression rises it means you have bad piston rings. If no raise you have bad intake or exhaust valves.
Your best bet would be to take it to the dealer for a diagnostic it will run you about anywhere from $140-$180 make sure to explain everything you've done to the vehicle and what's going on.
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