Compression test fail !

[unstopables_7]

hey guys, recently while servicing my car i just got my mech to check my engine and he suggest me to just do the compression test and guess what my fourth piston fail! only when up to 3bar while other 5 went to 8 bar.. but i did not believe it until its done 2-3 times because my engine runs perfectly and i dont feel any missfire or jerking..so.. anyone experience this? my mech say 2 ways to settle this 1-top overhaul (he said its the valve kaput)2-before doing that he asked me to find the best engine treatment and give a try first.. this may not solve 100% but maybe better according to him..any ideas guys..

 

[ramsing]

go to temple and pray v hard first....:listen:

 

[andrewk]

Get a 2nd opinion....

 

[ICEMAN 68]

any white smoke at the rear ? as during your genting hill climb did not see any smoke and you've been the champion lorrr ....

do you still able to take it to the max top speed ...

 

[unstopables_7]

any white smoke at the rear ? as during your genting hill climb did not see any smoke and you've been the champion lorrr ....

do you still able to take it to the max top speed ...

nop bro.. no white smoke and yes performance still good..top speed still rawks!:top:

 

[irfan80]

bro,

in the first place, what make ur mech suggested the compression test? any sympthom what so ever?

 

[unstopables_7]

bro,

in the first place, what make ur mech suggested the compression test? any sympthom what so ever?

All started when i had the hard start prob which eventually fixed after me changing my fuel pump.. cos they did the compression test and also fuel pump pressure test..

 

[pussy]

can I ask which car is this ?

 

[Chrix]

Like what Mr andrewk said, perhaps get a second opinion. Would not hurt, but just be ready if they give an entirely different diagnosis & leaving your even more confuzzed.

can I ask which car is this ?

I believe E36 M50.

 

[unstopables_7]

Yea bro 325 e36..
M50..

Will surely get a second tought on it .. Hurmm..

 

[ICEMAN 68]

All started when i had the hard start prob which eventually fixed after me changing my fuel pump.. cos they did the compression test and also fuel pump pressure test..

fuel pump pressure test ...how to do this on the fuel pump ... unless they check on the fuel regulator by replacing it ....


exactly ..as stated by @irfan ...why do a pressure test ?

 

[e34_lover]

fuel pump pressure test ...how to do this on the fuel pump ... unless they check on the fuel regulator by replacing it ....


exactly ..as stated by @irfan ...why do a pressure test ?

Usually there is a valve near the intake on the M50. If not, you can just tee in a pressure gauge and you can see your fuel pressure from there!

 

[unstopables_7]

Usually there is a valve near the intake on the M50. If not, you can just tee in a pressure gauge and you can see your fuel pressure from there!

Bro iceman .. Yeah thats what they actually did.. Thats the first time i saw it being done too,,

 

[e34_lover]

unstopables, do you know if they did a wet compression test as well to confirm that it is the valves and not the piston rings? A leakdown test will also help pinpoint your problem area by finding out where the leaks can be heard. If it truely is a bent valve, you will hear hissing in either the intake or exhaust.

If the mechanic is right about the valve being bent, then something must have happened. I don't think that a bent valve would allow the car to run as well as you said it does. Is your car auto or manual?

I am leaning more towards piston rings on that cylinder because your car isn't showing any symptoms of a bent valve. Try to see if you can do a wet compression test and let us know the results. A wet compression test is done by putting a little oil into the cylinder and testing compression. The oil will help the rings seal a little and should show better compression on that cylinder.

Hope this helps!

 

[unstopables_7]

unstopables, do you know if they did a wet compression test as well to confirm that it is the valves and not the piston rings? A leakdown test will also help pinpoint your problem area by finding out where the leaks can be heard. If it truely is a bent valve, you will hear hissing in either the intake or exhaust.

If the mechanic is right about the valve being bent, then something must have happened. I don't think that a bent valve would allow the car to run as well as you said it does. Is your car auto or manual?

I am leaning more towards piston rings on that cylinder because your car isn't showing any symptoms of a bent valve. Try to see if you can do a wet compression test and let us know the results. A wet compression test is done by putting a little oil into the cylinder and testing compression. The oil will help the rings seal a little and should show better compression on that cylinder.

Hope this helps!

no bro, i have not done the wet compression test not very sure on the hissing sound where i dont know how does it sound actually..haha

mine is manual btw and yeah its so strange because i can drive peacefully with no problem..

Appreciate this so much bro will defiantly talk to my mechanic and do a wet compression test soon and will look into the hissing sound..thanks bro!

 

[e34_lover]

no bro, i have not done the wet compression test not very sure on the hissing sound where i dont know how does it sound actually..haha

mine is manual btw and yeah its so strange because i can drive peacefully with no problem..

Appreciate this so much bro will defiantly talk to my mechanic and do a wet compression test soon and will look into the hissing sound..thanks bro!

I asked if you had manual because to bend the valves, you would have had to over-rev then engine. Did that happen at any point?

I hope the wet compression test produces some good results!

If you do end up pulling the head to check if its a bent valve, make sure you are there. Too many shady mechanics nowadays lol. I still think its a piston ring though.

Let me know if you need any other help!

 

[unstopables_7]

I asked if you had manual because to bend the valves, you would have had to over-rev then engine. Did that happen at any point?

I hope the wet compression test produces some good results!

If you do end up pulling the head to check if its a bent valve, make sure you are there. Too many shady mechanics nowadays lol. I still think its a piston ring though.

Let me know if you need any other help!

Actually yeah i did a few times , over-rev to the max actually .. could that just be it?

Will get the wet compression test done soon to be safe..

BTW bro after you pointing this up to me now i do believe its the valve bent cause i did over-rev it .. how serious can this be? i mean what else does over-rev cause?

 

[e34_lover]

Actually yeah i did a few times , over-rev to the max actually .. could that just be it?

Will get the wet compression test done soon to be safe..

BTW bro after you pointing this up to me now i do believe its the valve bent cause i did over-rev it .. how serious can this be? i mean what else does over-rev cause?

Ok when I meant over-rev, I am talking about changing down into the wrong gear at high rpms for example changing down from 3rd to 2nd instead of to 4th. This would cause the pistons and valves to hit.

From what it sounds like all you did was rev it to the rpm limit and bounce off the limiter? Shouldn't be a problem unless your timing is out which could cause valve piston contact.

Which one of these descriptions describe what happened to you?

 

[unstopables_7]

Ok when I meant over-rev, I am talking about changing down into the wrong gear at high rpms for example changing down from 3rd to 2nd instead of to 4th. This would cause the pistons and valves to hit.

From what it sounds like all you did was rev it to the rpm limit and bounce off the limiter? Shouldn't be a problem unless your timing is out which could cause valve piston contact.

Which one of these descriptions describe what happened to you?

ohh luckily , what i meant was over-rev it to the max , over 7000rpm .. if this happens frequent what will it cause? contact between piston and valves?

 

[e34_lover]

I think you would be fine bro. Won't have any contact unless your timing is way out. Good luck!