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Engine Specific Info and Questions => IDI Engine => Topic started by: vwnut84 on January 25, 2009, 02:55:36 pm
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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!
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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.
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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.
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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...
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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 ?
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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.
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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.
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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.
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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
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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:
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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.
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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. :)
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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:
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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.
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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
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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
Yeah, that's it. But, did you check the actual arm on the back side of the IP to see it was all the way to the timing belt ? The cable can come loose so your lever is in a partial pulled position.
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I actually did visually check the lever to make sure I had not bumped it cause that has bitten me in the ass before haha.
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Ok, so last night I brought it in, set the timing to .86, started it and let it run again. Still seems to be running the same.
So the car is running fine EXCEPT for; harder starting when cold, but fine when hot, and the engine is just louder then it used to be, I can only describe this as having more of a knock to it, like a harsher diesel sound, if that makes any sense at all haha.
So at this point I think I am going to order up a 2 notcher, and throw it in there this weekend, because the only thing different at this point is the different HG, so i figure I'll start at square one.
One thing I did find out is that the cold start on the pump actually does work. I moved it with the dial indicator in place and was pleasantly suprised, I think my cable is just siezed. Never bothered to mess with it cause I never really needed it. bonus! haha
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Ok so I get my new gasket and bolts ready, take off the valve cover, and set the engine back up at TDC. So as I am turning the crank my friend is watching the notch on the flywheel and he goes "hey there was another notch I think". At this point I poke my head over and low and behold there is ANOTHER notch about 7-8 degrees BTDC almost identical to the correct TDC mark. HAHA! Reset timing to the correct TDC and now the car is perfect again.
I KNEW it sounded like a timing problem. It's funny, whenever I have a problem like this it's always something really really dumb haha.
Thanks for all of the responses! :o)
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of course 8)
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of course 8)
I'm glad you got it straightened out after finding that other mark, I can't imagine how you ever got it started before living in New York with no working cold start lever as you can't always use the heater. :)