Mk 3 with engine fault
Discussion
A friend has just bought a 2.0li mk 3 Mx5 and had an engine light come on , obd reader says no3 cylinder misfire .
Apparently the light was on when he viewed the car and the garage assured him it would be sorted !
Anyway the car was delivered to him but the dreaded engine light re-appeared. This apparently after only a few miles .
A compression test revealed the following.
No1. 225 psi ( surely to high )
No2. 175psi
No3. 75psi ( ! )
No4. 185psi
A spray of oil into no 3 increased the compression to 120psi which I believe points to a piston / ring failure.
As no1 cylinder is high compression is it probably fair to assume they would all have been at that level .
Does this mean the head has been skimmed and possibly no’s 2&4 are heading the same way as no3 .
Is 225psi excessive for a standard engine . Seems high to me .
Only has 55k miles on the clock and the garage say they want the car back to repair it but my mate understandably wants a refund .
Anyone come across this kind of fault ?
Apparently the light was on when he viewed the car and the garage assured him it would be sorted !
Anyway the car was delivered to him but the dreaded engine light re-appeared. This apparently after only a few miles .
A compression test revealed the following.
No1. 225 psi ( surely to high )
No2. 175psi
No3. 75psi ( ! )
No4. 185psi
A spray of oil into no 3 increased the compression to 120psi which I believe points to a piston / ring failure.
As no1 cylinder is high compression is it probably fair to assume they would all have been at that level .
Does this mean the head has been skimmed and possibly no’s 2&4 are heading the same way as no3 .
Is 225psi excessive for a standard engine . Seems high to me .
Only has 55k miles on the clock and the garage say they want the car back to repair it but my mate understandably wants a refund .
Anyone come across this kind of fault ?
Just kick it back. You don't say what year the car is, but if it's an nc1 there is a well known and documented issue with piston rings closing up. Low compression is the least of the issues, it causes oil consumption which due to the manicat goes unnoticed unless you check level regularly. The engine runs low and then starts to knock as the bearings run dry.
He has perfect grounds for return. I wouldn't want it repaired if it was mine, even if it is only a head gasket (unlikely with those readings) the engine isn't known for gasket issues or burnt valves (another explanation).
Shameless plug. I did write a MK3 buyers guide for veloce publishing. It does describe many of the pitfalls.
He has perfect grounds for return. I wouldn't want it repaired if it was mine, even if it is only a head gasket (unlikely with those readings) the engine isn't known for gasket issues or burnt valves (another explanation).
Shameless plug. I did write a MK3 buyers guide for veloce publishing. It does describe many of the pitfalls.
wildoliver said:
Just kick it back. You don't say what year the car is, but if it's an nc1 there is a well known and documented issue with piston rings closing up. Low compression is the least of the issues, it causes oil consumption which due to the manicat goes unnoticed unless you check level regularly. The engine runs low and then starts to knock as the bearings run dry.
He has perfect grounds for return. I wouldn't want it repaired if it was mine, even if it is only a head gasket (unlikely with those readings) the engine isn't known for gasket issues or burnt valves (another explanation).
Shameless plug. I did write a MK3 buyers guide for veloce publishing. It does describe many of the pitfalls.
Would you post your buyers guide here ? He has perfect grounds for return. I wouldn't want it repaired if it was mine, even if it is only a head gasket (unlikely with those readings) the engine isn't known for gasket issues or burnt valves (another explanation).
Shameless plug. I did write a MK3 buyers guide for veloce publishing. It does describe many of the pitfalls.
Stan the Bat said:
wildoliver said:
Just kick it back. You don't say what year the car is, but if it's an nc1 there is a well known and documented issue with piston rings closing up. Low compression is the least of the issues, it causes oil consumption which due to the manicat goes unnoticed unless you check level regularly. The engine runs low and then starts to knock as the bearings run dry.
He has perfect grounds for return. I wouldn't want it repaired if it was mine, even if it is only a head gasket (unlikely with those readings) the engine isn't known for gasket issues or burnt valves (another explanation).
Shameless plug. I did write a MK3 buyers guide for veloce publishing. It does describe many of the pitfalls.
Would you post your buyers guide here ? He has perfect grounds for return. I wouldn't want it repaired if it was mine, even if it is only a head gasket (unlikely with those readings) the engine isn't known for gasket issues or burnt valves (another explanation).
Shameless plug. I did write a MK3 buyers guide for veloce publishing. It does describe many of the pitfalls.
TVRees said:
JimM169 said:
I'd be interested in this too....
You could always buy a copy of the book 
https://www.veloce.co.uk/store/Mazda-MX-5-Miata-p3...
Dave. said:
TVRees said:
JimM169 said:
I'd be interested in this too....
You could always buy a copy of the book https://www.veloce.co.uk/store/Mazda-MX-5-Miata-p3...
While I'll never get rich off the royalties (I'm lucky if I get a tank of fuel from it) I'm afraid the script can't be posted up.
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