Fiat Croma 1.8 16v (Engine : Z18XER) Low compression

**lukasSVK1** · 1st November, 2019, 06:57 PM

Hi, I need your help ,
The car was underlining , starting badly and so on. In the car there were changed rings, gasket under the head. After measuring the pressures, almost every cylinder had a pressure of 90 PSI. I read more about this engine and found that the valve clearances had to be adjusted. I found on the Internet what the valve clearances needs to be. I measured the clearance and on intake it was from 0.05mm to 0.13mm which is very little, on the exhaust were from 0.15mm to 0.25mm. I thought the pressure was leaking because of poor valve clearance, as it was practically ajar while compression was happening. On the Internet I found the range and ideal valve clearance. I let the valve taps grind down and put everything back together. This time there is very little difference ... Cylinder 1 - 90PSI, Cylinder 2 and 3 - 100PSI, Cylinder 4 - 110PSI ... Normally, the engine should have a pressure of about 200 PSI (14-16 bar).

Any advice ?

**autoden** · 2nd November, 2019, 11:46 AM

What about EGR?

**DiegoStud** · 2nd November, 2019, 12:14 PM

Originally Posted by lukasSVK1

it was practically ajar while compression was happening.

How long has it been running like that?
#burntvalves

**lukasSVK1** · 3rd November, 2019, 10:50 AM

Originally Posted by autoden

What about EGR?

Car is Petrol not Diesel , so I do not have EGR . Car is modified to run on LPG . But the LPG is not the problem.

Originally Posted by DiegoStud

How long has it been running like that?
#burntvalves

Well I bought this car in January 2019 , At that time car was going pretty well ... But it was firing from the exhaust . I think it was burning badly. In September the car started to underline really badly . Bad starts etc.
So was running like month like this. We were scared to drive it so we just didnt drive it for a while. But there are no burn valves. Why ? Engine Head and valves were ground (or grinded ? Sorry for my bad English). That man who were grounding / grinding my Engine head showed me that there are no burn valves.
Even In the car there were changed rings, gasket under the head.
So I do not know what's happening. Now the car is starting pretty good and it's not underlining. But the power of 103kW(140 HP) is gone. Because of compression.

**DiegoStud** · 4th November, 2019, 12:35 AM

Originally Posted by lukasSVK1

Well I bought this car in January 2019 , At that time car was going pretty well ........Now the car is starting pretty good and it's not underlining. But the power of 103kW(140 HP) is gone. Because of compression.

So it was running better before you took the head off? VVT mechanisms on these. Check your valve timing.

Throttle open when testing compression?

**lukasSVK1** · 4th November, 2019, 04:42 PM

Originally Posted by DiegoStud

So it was running better before you took the head off? VVT mechanisms on these. Check your valve timing.

Throttle open when testing compression?

Valve timing is good, i think. But to be sure I will check it again.

No .. , compression was tested without throttle.

Thanks for your advice , will check Timing again and test compression with open throttle