Engine knock with chipping is fairly common in the 1.8. The knock sensor only has a limited range from which to retard the timing, then it knocks. The chips are advancing the timing and hoping that you have the octane to support it.

Surging when accelerating, particularly 2nd-3rd gear is often the knock sensor cutting back timing. Knock is very hard to hear due to the excellent insulation and doule fire wall. Run with the windows down and give it full-throttle in 2nd/3rd when passing by a wall/bulding/tunnel.

If it rattles, rocks in a can, "wasps", etc., LIFT YOUR FOOT! You gas octane is too low. I have a half-dozen posts on this in the archives. MANY gas companies/distributers/retailers cheat on octane levels. I have had "91 octane" that knocked with 2 cans of NOS octane boost.

It is important to remember that you must listen for the knock when changing gas brands, travelling, and with the changing seasons. Also, be sensitive to surge, that is the first sign. Knock is the one thing that will hammer the motor in no time flat.

 

Good posting - so many people here make mods without enough knowledge of cars.

 

I TOTALLY AGREE DON'T JUMP ON THE "CHIP IT" BANDWAGON UNTIL YOU'VE DONE YOUR HOMEWORK!

 

Then again, a lot of people post info that is incorrect or misinformed as well

 

Wink, wink. Nudge, nudge, Know what I mean?

 

??

 

If all you hear is one or two little high pitched "tink" sounding noises very occasionally when its hot out, or you got poor gas, then there is nothing to worry about. If it's only once or twice, then the knock sensor IS doing its job, and preventing any damage from occuring. To say that chipping alone will somehow totally overload the knock sensor is completely naive, and irresponsible. Audi doesn't even make a big deal about cool down in these cars, and the octane rating of 92 is only "recommended" I really doubt they would willing be obtuse when it would cost them warranty turbo replacements left and right. This engine is tougher than you think. I have a personal opinion that the surging is more a case of the stock diverter valve not being able to handle the sustained boost of a chip, rather than the knock sensor wailing away. This will either be borne our or refuted when I put in a Bailey DV (when they finally come off backorder!).

Continous hard pinging that you can feel as well as hear is complete detonation, where the fuel/air combo is spontaneously igniting before the piston reaches top dead center of its stroke. This IS very bad and can eventually cause (read, not instantaneous) evere engine problems. I don't think this is the case for 99% of the people here who complain of pinging problems. Instead of the complete pre-ignition, like detonation, pinging is usually just caused by uneven flame-front generation and sometimes multiple flame seeds. I've heard that the pinging sound in these cases is just the slightly overlapping shock waves "echoing" as they cross each other in the cylinder.

In the two years since I've been on this forum I can't recall a single engine or turbo failure that was traced to a chip alone, in fact nearly all the K03 turbo failures in a 1.8T that I can remember were in 97's and early 98's that didn't have the oil line heat shielding.

I agree that you should have a good understanding of how the entire engine and turbo works before making modifications, that way you have the knowledge to help diagnose any problems, but your alarmist tone is overblown, and may turn someone off to enjoying their car more fully. There is SOME truth in all your statements, but also A LOT more to them if you look a little deeper.

 

My point is the occasional ping isn't even going to be noticed. I'm talking about full-on detonation that even people standing 20-ft away can tell.

I have had this with two different chips and more tanks of gas than I can remember. All now resolved. Surging was exclusively the retard. Also now resolved. Although I agree that the Audi diverter/recic. is junk.

The motor is a tank. I have been the first voice on the gomers babbling about 1.8 turbo/engine failures, no substantiations for that engine combo (97-98 none from my investigations). Unnoticed knock, which I describe, will cause a ring to break, ending that cylinder.

I was not being alarmist in any sense. This engine was MEANT to be chipped. But the unaware are going to get stung at some point (re. 89 octane chippers that post here, or folks who don't recognize knock).

 

It makes a lot more sense that you were just talking about true detonation. Sorry if I came off the wrong way, I agree with you fully now.

There are plenty of clueless newbies around, and even though I don't claim to know everything, it seems like there are also a lot of those exibiting "a little knowledge is a dangerous thing" syndrome who understand somewhat, but just enough to confuse themselves and others.

BTW, can you email me off board about the details of your car (MY etc.) and which chip manufacturer it was that you had the problems with and what they did in the programming to fix it? Thanks.

 

Just got my Bailey, and it did correct the surge.