Interpreting My Compression Test

[Cup1/2Full]

02 172 Cup 135K

This started when I took the car to be remapped at Engine Dynamics only to be told the car was making 150bhp and was un tunable.

So I bought a decent ish compression tester from Laser after watching Youtube recommendations.

I did three tests on each cylinder dry and wet, cranking the engine for 5-6 seconds and the results were consistent each time.

From the gearbox side:

Dry Cyl 1. 160psi Cyl 2. 160psi Cyl 3. 140psi Cyl 4. 170psi

Wet Cyl 1. 200psi Cyl 2. 200psi Cyl 3. 200psi Cyl 4. 190psi

I don't know what it should be, but as the wet test was so much different, I assume the added oil was sealing the worn pistons?

As you can probably tell I'm pretty much just a monkey poking a rock mechanically speaking

So is it a new engine or rebuild time?

Cheer's

 

[JamesBryan]

Dry test results aren't too bad, although no.3 is a little lower.

I've seen them make book power on similar compression.

I'd be looking at timing.

 

[Cup1/2Full]

Dry test results aren't too bad, although no.3 is a little lower.

I've seen them make book power on similar compression.

I'd be looking at timing.

Engine Dynamics said that could be the cause.

The belts were done at the main agents with the correct tool by a 22 year experience Ren Master tech, and he's saying the engine's knackered. I suppose its worth getting somebody else to check the timing.

The other thing to note were that the top of the inlet manifold that holds the coil packs seems to be warped. It doesn't seem to fit too well and I had a few go's at refitting it due to starting the car and it bouncing of the rev limiter.

The other thing is both the gaskets on the inlet manifold have seen better days.

 

[JamesBryan]

Engine Dynamics said that could be the cause.

The belts were done at the main agents with the correct tool by a 22 year experience Ren Master tech, and he's saying the engine's knackered. I suppose its worth getting somebody else to check the timing.

The other thing to note were that the top of the inlet manifold that holds the coil packs seems to be warped. It doesn't seem to fit too well and I had a few go's at refitting it due to starting the car and it bouncing of the rev limiter.

The other thing is both the gaskets on the inlet manifold have seen better days.

When you say main agents, do you mean a Renault dealer?

Take it to Alex at AW Motorworks and get him to check it, he used to work for Engine Dynamics.

He's the best in the area.

https://www.facebook.com/AWMotorworks/

 

[Cup1/2Full]

When you say main agents, do you mean a Renault dealer?

Take it to Alex at AW Motorworks and get him to check it, he used to work for Engine Dynamics.

He's the best in the area.

https://www.facebook.com/AWMotorworks/

Yeah Renault dealer.

I've emailed Engine Dynamics but they are out of the office till Monday. I'll either take it to them or AW.

Cheer's

 

[R3k1355]

Be very lucky to find a mechanic at a Renault dealer thats done the belts on a 1*2 before, whereas the known specialists will do them all the time.

Was the motor upto operating temperature when you did the compression tests?

 

[Cup1/2Full]

The engine was up to temperature, with a fully charged battery, however I did not open the throttle when I did the wet and dry test's

 

[R3k1355]

Redo it with the throttle wide open, can make a big difference on some engines.

 

[Ol’ Tarby]

You'd of had to of had the inlet plenum off to do the test? So the throttle would of been "open"

 

[RSRowe]

Compression test is a waste of time imo. Leak down would give you a clearer picture tbh

 

[Cup1/2Full]

You'd of had to of had the inlet plenum off to do the test? So the throttle would of been "open"

That makes sense, as the throttle body was on the floor behind me