Valve Seat Recession and LPG - myth or not?

[stooy Junior Member Find all posts View Profile Close stooy]

G'day Everyone,

I was wondering if anyone has ever had trouble with valve seat recession on a 4.0 V6?

If so were you on LPG?

The reason I ask is I have been having trouble with O2 sensors in my right bank so I took my car to an Auto Diagnosis specialist who told me that "This is the worst possible engine to put on LPG, they give trouble on petrol and on LPG this will be an ongoing issue". I am struggling to believe this to be honest and keen to hear if other people have had troubles.

For reference my car has a JTG liquid system on it and has done about 110,000kms with it. 30,000 or so have been fairly hard kms towing 2.5 tonnes.

Cheers

Stewart

[drwormy Junior Member Find all posts View Profile Close drwormy]

Ive put 120,000 on LPG on my FJ with no issues, and know some that have done more.

Hilux has the same engine as the P120 - Prins Autogas has a Hilux with ~ 500,000 kms on it on LPG.

https://www.facebook.com/search/top/...ia%20Pty%20Ltd

[stooy Junior Member Find all posts View Profile Close stooy]

Thanks Mate, I compression and leak down tested my car on Saturday. Lowest compression test was 167psi most were 177-183psi and one was 189psi. The leak down test was fine also. I call BS on my car having dead valves.

[GEEEXL Member Find all posts View Profile Close GEEEXL]

how many kays total?

fairly big variance in compression.. variance is not a good sign

[gazgofishing Lurker Find all posts View Profile Close gazgofishing]

Have your tappets adjusted.They use a bucket and shim adjustment. Important on gas vehicles.

[thebaz Junior Member Find all posts View Profile Close thebaz]

Not sure if this is relevant, but i am doing the timing chain on my 1GR-FE and it has done 266k and not been serviced well at all. It is straight petrol but I was surprised that when i checked the valve clearances they were all within spec. I am sure LPG would take it's toll on guides and valves, but they must be pretty hardy to be still within spec after 266K.

[stooy Junior Member Find all posts View Profile Close stooy]

Thanks Guys. I plan to get the valve clearances checked shortly. The car has done 175k so far.