Lost Cylinder Compression

[DeathSammich]

Have a recent rebuilt l67 and lost compression in 2 cylinders. Both around 60psi. I have new heads to put on it but was just wondering, if 2 cylinders are down on compression would that cause a major increase in fuel consumption? Like 16-18l per 100 average? Thanks

 

[delcowizzid]

Are they 2 cylinders side by side

 

[EYY]

2 bad cylinders will definitely give increased fuel consumption

 

[DeathSammich]

Are they 2 cylinders side by side

Passenger side 140, 75, 60

 

[DeathSammich]

2 bad cylinders will definitely give increased fuel consumption

Like a really big hit in consumption or only a little?

 

[delcowizzid]

Looks like you'e blown the head gasket between those 2 cylinders

 

[DeathSammich]

Looks like you'e blown the head gasket between those 2 cylinders

Nah engine has been rebuilt twice. Mechanic said rings but it was clearly the head. Its probably warped or cracked. I got another set to put on.

Do you reckon the low cylinders would cause a major bump on fuel consumption?

Looks like you'e blown the head gasket between those 2 cylinders

 

[delcowizzid]

Well it' running on 4 cylinders so yeah fuel consumption through the roof lol.normally when 2 side by side both lose compression its the gasket blowing between the 2 cylinders cracked heads won't lose compression like that .valves not closing would or smashed rings do a leak down test plug compressed air into one of the low comp cylinders with the rockers undone you'l soon find where the airs going it will be gushing out either into the crankcase from rings out the exhaust or intake if its valves out the cylinder next doors plug hole if it' the gasket or bubble out the Radiator if its cracked the head or blown the gasket to water

 

[Immortality]

Passenger side 140, 75, 60

Classic blow head gasket between the cylinders numbers.

It's going to be a head off job regardless.

edit: find a new mechanic...

 

[delcowizzid]

Probably damaged the gasket a little when you had the l36 Injectors in it by accident and boost has finished it off over time