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View Full Version : Low on power: Vanos good, DISA good



ziazhp
06-27-2019, 03:22 PM
Hi Guys,
Looking for some insight as to where to go next to regain low end torque on my ZHP. I recently replaced the vanos unit with a rebuilt one from Dr. Vanos. This definitely made a difference, but low end torque is still not where I think it should be. The car does run better and picks up better on the highways, but general city driving isn't very quick. I checked my DISA valve today, it seems solid, holding vacuum when testing it, the pin isn't loose, etc, it does have around 70k mi on it though... I've had a smoke test done, no leaks, no codes, etc. Any ideas? I'm robbed being at moderate altitude (5k ft), but in general my ZHP does not seem as peppy as say my brother's 01' 330xi. My car has around 164k on it at the moment.

ziazhp
06-27-2019, 03:25 PM
I'll also add that my gas mileage is not great, around 315 last fill up and I haven't been driving aggressively. This is city driving, but I'd expect at least 350+ or so. In the past I have gotten 420+ to a tank driving 90+ on the highway..

az3579
06-27-2019, 04:00 PM
Perhaps your cat is clogged. That was my issue. All other maintenance items were up to date but still had terrible power and fuel economy. Maxxing out third gear was agonizingly long and was lucky to get much past 25mpg on the highway when normally I could easily get over 30.

Once I replaced them, I got most of the power and fuel economy back.

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RUS_ZHP
06-28-2019, 05:26 PM
That's right, Botond is the expert for clogged cats considering his mileage-:)

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sparky300
06-28-2019, 05:49 PM
I might suspect one or both of the pre-cat O2's but I'd have to do some searching first to find the acceptance range values

az3579
06-29-2019, 05:53 AM
I might suspect one or both of the pre-cat O2's but I'd have to do some searching first to find the acceptance range valuesThis is the video I used to determine whether the values the post-cat O2 sensors are reading are within range. I used the Torque Pro app on my phone and an OBD2 Bluetooth adapter. You can also used INPA if you have it.

https://m.youtube.com/watch?v=aTNhxvyesPs

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ziazhp
06-30-2019, 03:37 PM
Thank you everyone for the replies, much appreciated.

sparky300
06-30-2019, 07:50 PM
Where in NM are you?