cylinder 4 0compression

[jr_1086]

just finished doing a compression test on one of my tsi's and cylinder 4 read 0 compression so i put a cap full of oil and did it again yet read 0 so its not the rings. a friend told me its probably the valves. is this true? or should i do a leak down test?

 

[biker_joe89]

Do a leakdown test before you go pulling it apart. At least that is what I would do.

 

[rx7ttlm]

its hard to get 0 compression so you have to have something big going on.

 

[jr_1086]

well the needle jumped up but went down to 0 right away in a matterof seconds cylinder 1 read 150 2 read 147 andthe 3rd read 145

 

[hubz91talontsi]

What was the reasoning behind doing a compresson test? Car stopped running?

 

[luv2rallye]

Valve stuck open or blown head gasket.

 

[Derock2gspyder]

leak down test is the best way to start but yes most likely valve or broken spring in the head!

 

[400hp93talon]

With the other cylinders having pretty good compression Im doubting it's the bottom end.....like luv2rallye said it's most likely a valve stuck open(or bent) or the head gasket blew out on that side. Either way You need to pull the head off!!

 

[KadieTSi]

Something else you can do is check the timing and see if it has jumped

 

[90on35psi]

Definately sounds like a valve problem or the head gasket but is also odd being 0psi. Something is definately not sealing in there.

 

[BogusSVO]

try another compression tester.......

 

[SupaDoopa]

Another tester is where I'd start.

 

[jr_1086]

the reason for the compression test is i bought the car in indiana but car ran like crap like it was on 3 cylinders so i did the compression on the spot before purchasing it. brought it home changed spark plug wires and plugs and the coil then did the compression test again with a new tester an still same result. well cylinder 4 the needle on the tester will jump very lightly but right away will go down to 0. im pulling tehead off hopefully next week and will try and post up some pics and hopefully a video of 1 more compression test before pull i the head.thanks guys for all the responses

 

[BogusSVO]

if you have run the test twice and 0 on 2 diffrent gauges, bent/stuck valve

inject and hold shop air into the cylinder (at TDC) then listen at the TB, if you hear air escaping here, bent intake valve, if you hear it at the tail pipe, then bent exhaust valve

if you hear it out the oil filler hole. hole in the piston