Pinging with EAT chip...'94 525iT

[rizal]

I live in San Diego, have a '94 525iT with 127K miles, put an EAT chip in it several motnhs ago. Runs very nicely. However, even on 91 octane, I get light pinging on light throttle, which cleans up well with more throttle. How much is OK? Should there be zero? Any way to diagnose whether this is causing harm?
Thanks very much. Al

[MarkD]

I live in San Diego, have a '94 525iT with 127K miles, put an EAT chip in it several motnhs ago. Runs very nicely. However, even on 91 octane, I get light pinging on light throttle, which cleans up well with more throttle. How much is OK? Should there be zero? Any way to diagnose whether this is causing harm?
Thanks very much. Al

In general, ping is not good. but a small rpm range such as 2200 to 2600 at light load (throttle) isn't going to destroy your motor. For some reason, there are a certain number of m50tu's that have a tendency to ping, and some even do it with a stock chip. I've got a feeling that it is caused by the MAF going a bit out of spec. (and making the motor run a bit lean).

The cars that ping like yours does also do it with Dinan and Conforti chips.
I am hopind o make a new version just for cars that have this problem. I did make a test version for someone in CA (Phil Lau) who has not posted here in at least a year, and he said it helped quite a bit.

MarkD

[RobPatt]

Rizal, can tell you I've had the EAT for the last about 30K miles on a '93 525i w/the same engine as you and DO experience a minor ping (or some other rattling) in the same RPM range under light acceleration. I always run Chevron or Shell highoctane. But can also say Mark is right, this has been well discussed on the forum here, and most of us w/this engine experience the same thing. Personally I don't know if it's pinging, think it is. Most of us do our own maint and run Mobil 1 0w40 (is this relevent?)

Mark, I'd be willing to test a prototype if you like. ( I bought your EAT about 3 years ago during a Christmas special you were running ).

Keep the EAT and remember to give it a good drive on the highway every now and then, and use good clean quality gas, eliminate vaccuum leaks etc.


....maybe we've all got a little vaccuum leak in the same hose in the same place (under the intake mani?) and we all just don't know it? Small enough not to throw any error codes, but enough to ping under a different engine mapping? Who knows.

still happy,
Rob.

[Bill R.]

slight buildup on the thin film or thick film depending on which type it is , which causes it to run slightly lean and ping under low throttle application , Cleaning the air intake side of the maf using throttle body cleaner takes care of the problem. Throttle body cleaner not carb cleaner. Carb cleaner can damage a thick or thin film sensor. On the fords and chevies that this is most predominant on it takes care of the problem and clears up the slight hesitation that usually goes hand in hand with this.

In general, ping is not good. but a small rpm range such as 2200 to 2600 at light load (throttle) isn't going to destroy your motor. For some reason, there are a certain number of m50tu's that have a tendency to ping, and some even do it with a stock chip. I've got a feeling that it is caused by the MAF going a bit out of spec. (and making the motor run a bit lean).

The cars that ping like yours does also do it with Dinan and Conforti chips.
I am hopind o make a new version just for cars that have this problem. I did make a test version for someone in CA (Phil Lau) who has not posted here in at least a year, and he said it helped quite a bit.

MarkD

[rizal]

Thanks very, very much for the sage responses. Much better than I expected.
Mark, I too would be interested in trialing one of your revised chips if you're interested.

Thanks again. Al

[Trevor]

I got one of the first OZ EAT chips from MArk and had the intermittant pinging after 1-2 weeks of use.
Recently I have put the ccip back in and on 91 octane the pinging was painful.
Filled up yesterday with 95 octane and the problem has almost gone.
Fingers crossed.

[Anthony (M5 in Calgary)]

slight buildup on the thin film or thick film depending on which type it is , which causes it to run slightly lean and ping under low throttle application , Cleaning the air intake side of the maf using throttle body cleaner takes care of the problem. Throttle body cleaner not carb cleaner. Carb cleaner can damage a thick or thin film sensor. On the fords and chevies that this is most predominant on it takes care of the problem and clears up the slight hesitation that usually goes hand in hand with this.

Bill, would you do the same cleaning to a hot wire MAF like the one on my M5? Any tips?

[kev535i]

I got one of the first OZ EAT chips from MArk and had the intermittant pinging after 1-2 weeks of use.
Recently I have put the ccip back in and on 91 octane the pinging was painful.
Filled up yesterday with 95 octane and the problem has almost gone.
Fingers crossed.

I recently had this conversation with Mark - to convert US octane to Aus octane you just add 4 ie 91 US = 95 Aus. Eat chips are designed to run on premium unleaded 95 or greater in Aus . you should try 98 and you will really appriecate the chip

[grave77]

I would say the same ... lower octane cause more pinging, I bought mine few monthes ago from e-bay and I use 98 octane and it runs excellant, while I think Mark made it on octane 95. it's for Mark to comment about the 98 octane as BigKriss also use 98 octane on EAT Chip.

[ryan roopnarine]

count me in as one of the US people that has knock on US premium (93 AKI) with their EAT. before i developed my vacuum leak (when i had my engine in extraordinarily good condition), i had the ping around the 2k area. i have a slight hunt in idle right now, so i will refrain from speaking about running condition right now. i think its somewhat disingenuous for some (not Mark) to suggest the US users up their fuel octane to fix the issue. the lowest octane that can be sold as "premium" in the us is 91 aki, or 95 RON. problem with that is that almost NO ONE sells 91aki, premium in the US now generally is 93 aki or slightly higher (97 or 98 RON). the grades sold here are (RON): 87, 89 or (91-93) premium. mark tells us to use "premium unleaded only", which everyone does.

someone asked about the hot-wire cleaning. i have the hot wire MAF (not the hot film maf like vanos m50s have), and i clean it with contact cleaner periodically. i have a PS leak which, i think is creating an oil spray underhood, and contaminating it slightly, as no matter how much i clean it, a "oily" looking residue remains, i can see the rainbow when the wire is still wetted.