Author Topic: Wrong notch headgasket cause poor running? (Read 5231 times)

vwnut84 · « **on:** January 25, 2009, 02:55:36 pm »

Ok, so I tore into my headgasket job on my Rabbit only to find I had been sent the wrong gasket. It's a 3 notch vs. a 2 that is on the car. So I figure I'm this far into it, I'll just try it. Bolted everything back up and fired her up only to find some rather unpleasant knocking noises, and a very rough running engine.

The first thing I did was re-check timing and all is spot on (pump is at 1.00mm) So I am thinking that the now effectively larger combustion chamber is causing problems. Just want to re-affirm this. Thanks!

dillenger1 · « **Reply #1 on:** January 25, 2009, 03:55:45 pm »

I wouldnt think it would be that poor.My engine was fitted with a 3 notcher,but called for a 2 and it ran fine.Although ultimately it lowers compression.

boosted_diesel_84 · « **Reply #2 on:** January 25, 2009, 05:22:49 pm »

Quote from: "dillenger1"

I wouldnt think it would be that poor.My engine was fitted with a 3 notcher,but called for a 2 and it ran fine.Although ultimately it lowers compression.

It wont lower it enough to matter or make any difference.

jtanguay · « **Reply #3 on:** January 25, 2009, 07:24:01 pm »

Quote from: "boosted_diesel_84"

Quote from: "dillenger1"
I wouldnt think it would be that poor.My engine was fitted with a 3 notcher,but called for a 2 and it ran fine.Although ultimately it lowers compression.

It wont lower it enough to matter or make any difference.

in extremely cold weather it will actually affect the starting ability. but it will run just fine. just because it runs fine, doesn't mean its running the way it should though...

arb · « **Reply #4 on:** January 25, 2009, 07:38:32 pm »

We don't all agree on how much the wrong gasket changes compression ration, but we all agree it will not make it run that poorly as the change is between no change and slight change....

So, problem likely is - Cold weather, maybe your timing ?

Vincent Waldon · « **Reply #5 on:** January 25, 2009, 07:44:51 pm »

Quote from: "arb"

We don't all agree on how much the wrong gasket changes compression ration, but we all agree it will not make it run that poorly as the change is between no change and slight change....

Very well put.... OP I think you're going to need to look elsewhere for the cause of your troubles.

jtanguay · « **Reply #6 on:** January 25, 2009, 08:33:22 pm »

Quote from: "vwnut84"

Ok, so I tore into my headgasket job on my Rabbit only to find I had been sent the wrong gasket. It's a 3 notch vs. a 2 that is on the car. So I figure I'm this far into it, I'll just try it. Bolted everything back up and fired her up only to find some rather unpleasant knocking noises, and a very rough running engine.

The first thing I did was re-check timing and all is spot on (pump is at 1.00mm) So I am thinking that the now effectively larger combustion chamber is causing problems. Just want to re-affirm this. Thanks!

maybe go into further diagnosis... how was it running before you changed the gasket? any bubbles going to the pump? a compression test would be very useful for diagnosis... does it run good when its up to temp?

did you clean both mating surfaces when you did the HG job? why did your rabbit need a new HG? overheat? the head could be warped if thats the case... then it would need a bit more work... you might get away with just having it planed, or it might need to be line bored as well if its bad. did you remove the bolts in the proper sequence, and then re-install new ones in the proper sequence? i assume you have the bentley?

just going over some basics... the more things you can answer the better the response will be in terms of figuring out whats the problem.

vwnut84 · « **Reply #7 on:** January 26, 2009, 05:39:08 am »

It was running fine before the job, the reason of replacement was for a coolant into combustion chamber leak, no overheating. I did remove and reinstall the bolts in the correct order, and yes I do have the bently.

Timing was the first thing I checked, and it's spot on. I did not let it run long enough for it to even start to warm up, as the knock was really loud. I'm going to pull it in the garage tonight, let it warm up, and see how it goes, maybe I got some crap in an injector when i had the head off.

Thanks for the responses guys, I didn't think that the different HG would have caused this much trouble.

vwnut84 · « **Reply #8 on:** January 26, 2009, 05:53:08 am »

You know another thing that just occured to me is that I only cracked the lines open till I got fuel flowing to them, I may have some air on one or two (where the knock seems to be) which could cause an injector knock, hmmm.....

I hate being at work not being able to just go outside and futz with it haha

jtanguay · « **Reply #9 on:** January 26, 2009, 07:47:19 am »

Quote from: "vwnut84"

You know another thing that just occured to me is that I only cracked the lines open till I got fuel flowing to them, I may have some air on one or two (where the knock seems to be) which could cause an injector knock, hmmm.....

I hate being at work not being able to just go outside and futz with it haha

if you got fuel out of all 4 injectors, then it should be fine. any air in the lines will be bled out within mere seconds of cranking after that.

i'd say start it up again, and crack each injector line till you find the suspect injector. it is possible that crap somehow fell in. obviously when the noise goes away, you'll know which injector to replace :wink:

arb · « **Reply #10 on:** January 26, 2009, 08:26:47 am »

Quote from: "jtanguay"

Quote from: "vwnut84"
You know another thing that just occured to me is that I only cracked the lines open till I got fuel flowing to them, I may have some air on one or two (where the knock seems to be) which could cause an injector knock, hmmm.....

I hate being at work not being able to just go outside and futz with it haha

if you got fuel out of all 4 injectors, then it should be fine. any air in the lines will be bled out within mere seconds of cranking after that.

i'd say start it up again, and crack each injector line till you find the suspect injector. it is possible that crap somehow fell in. obviously when the noise goes away, you'll know which injector to replace :wink:

If you pull an injector, don't forget to replace the disc.

vwnut84 · « **Reply #11 on:** January 27, 2009, 05:23:32 am »

Ok so I pushed the little guy back in the garage, threw on the block heater and warmed it up for a bit. Came back out and started it, and proceded to look for the bad injector, only to find that they all seem to be good. The car is running on all 4 and now idling and running smooth, but I still have a knock that was not there before. It almost sounds like the pump timing is too far advanced (like that marbles in a can sound when you rev it and at idle). So i checked it again (third time) and it's still spot on. (1.00mm)

In the bently it calls for somewhere around .83 for the pump with a white dot and like 1.10 for the pump with a yellow dot (something like that) I'm going to try to back it down to .83 tonight when I get home and see if that helps.

Thanks for the resposnes so far, keep em comin.

jtanguay · « **Reply #12 on:** January 27, 2009, 06:48:56 am »

Quote from: "vwnut84"

Ok so I pushed the little guy back in the garage, threw on the block heater and warmed it up for a bit. Came back out and started it, and proceded to look for the bad injector, only to find that they all seem to be good. The car is running on all 4 and now idling and running smooth, but I still have a knock that was not there before. It almost sounds like the pump timing is too far advanced (like that marbles in a can sound when you rev it and at idle). So i checked it again (third time) and it's still spot on. (1.00mm)

In the bently it calls for somewhere around .83 for the pump with a white dot and like 1.10 for the pump with a yellow dot (something like that) I'm going to try to back it down to .83 tonight when I get home and see if that helps.

Thanks for the resposnes so far, keep em comin.

i bet the noise will go down when you time it to .83 :wink:

arb · « **Reply #13 on:** January 27, 2009, 08:40:49 am »

Is your idle control pushed all the way in ? Is the arm all the way to the timing belt side of the IP ? It changes the IP timing.

vwnut84 · « **Reply #14 on:** January 27, 2009, 11:40:25 am »

If by idle control you mean the cold start lever, then yes, it is "pushed in" and it never worked anyway so I've never moved it. haha