No Compression???

[Tonks4x4]

Hi Chap's just want to run this one by you lot...

My mate bought my old cabby with the 7A engine in it. He has had it several weeks but has been giving it a fair fist full of right foot everywhere. The other night after bouncing off the rev limiter in 1st 2nd and 3rd it started smoking very heavily and then cut out. (White/Grey Smoke).
He has asked me to have a look, so went up to Sheffield the other night.

It has not used any oil,
It has not lost any water,
It is getting fuel at the correct pressure,
It's getting a clean spark to all cylinders.

So did a compression test and all 5 cylinders are below 4 bar???
Now the engine has only done approx 20k since all new rings and complete rebuild. So what on earth could cause the drop in compression on all cylinders?

I would expect 1 possibly 2 to be down if there was some critical damage.

The cambelt is still intact and the cam chain is still turning both cams.

The only thing I can think of since I have been up there is if the timing has jumped a tooth I will have to check that next time I go over.

Any ideas welcomed....

[chezz]

crank pulley failure? Harmonic damper been removed at any point and not torqued up correctly?

[Ruffiano]

After reading just the first half, i thought timing belt slipped. obviously you thought of that, That is the first thing I would check.

[LSG]

low compression

I no this may be a stupid thing to ask but he a,nt put diesel in the tank. The second thing is put oil down the bore then re do compression test see if it comes up.Do you have access to a leak down tester this would help you greatly.I hope you don,t think i,m a:corey: for asking the first question.only an.......

[Error404]

slipped tooth, shattered dizzy gear and washed bores?

[chezz]

My mate bought my old cabby with the 7A engine in it. He has had it several weeks but has been giving it a fair fist full of right foot everywhere. The other night after bouncing off the rev limiter in 1st 2nd and 3rd.... So what on earth could cause the drop in compression on all cylinders?

Driving like a total tool?

[Tonks4x4]

I no this may be a stupid thing to ask but he a,nt put diesel in the tank. The second thing is put oil down the bore then re do compression test see if it comes up.Do you have access to a leak down tester this would help you greatly.I hope you don,t think i,m a:corey: for asking the first question.only an.......

No don't panic I asked him the same quaestion as soon as he told me but he still had the receipt in his pocket from the last time he filled up....

I did pump some out in to a pot and light it aswell to make sure..

[Tonks4x4]

slipped tooth, shattered dizzy gear and washed bores?

I did check the dizzy the rotor was a little sloppy but the drive gear was intact.

[wildoliver]

I suspect there has been some piston/valve interaction resulting in loss of compression.

If he's been bouncing it off the limiter it's even possible it's had valve bounce resulting in the problem, or a slipped belt.

[JP]

Check that the cam caps are tight. They are reknowned to come loose when bouncing them of the limiter.

[GazzaG60]

ig go with that maybe or valvetrain issues.

[LSG]

One down.

No don't panic I asked him the same quaestion as soon as he told me but he still had the receipt in his pocket from the last time he filled up....

I did pump some out in to a pot and light it aswell to make sure..

Thats good, You can get the tax back on the receipt then Did you try the two other things i suggested ?? The car is insured for fire i take it with you about :mischeif: maybe it should be

[Ian Simmonds]

Really silly question, but are the valves closing properly? Or has it got multiple broken/bent valves/springs?

[Tonks4x4]

I am waiting for him to get it recovered to my place so I can have a good look at it

[LSG]

One down.

No don't panic I asked him the same quaestion as soon as he told me but he still had the receipt in his pocket from the last time he filled up....

I did pump some out in to a pot and light it aswell to make sure..

Thats good you can get the vat back on his receipt Did you try the two other things i suggested??. Has the car got fire insurance with you around it maybe a good idea :mischeif: