K&N on PD130 - have I killed my MAF?

[James_H]

I have an Octy PD130 and fitted a K&N panel filter to it instead of the usual OEM paper one. Performance of late seems fine most of the time but economy is noticeably poor. I can't get much more than low 40s mpg, sometimes only low 30s (urban but not stop start crawls). I don't know how reliable the dash indicator is but you can often see it sometimes shows reasonable mpg, sometimes very low pretty much the same conditions.

One possibility is that the MAF is on the way out and overfuelling the engine, hence the same power but poor mpg. Certainly the opposite of when the MAF failed on my Leon where power vanished. Searching back through the threads has found mixed views on replacement filters - many say there is no problem, others say it can be a known problem.

The car has done 77k, so could be due a new MAF anyway. I don't have a VAG-COM or a laptop, but realise I out to get it checked before shelling on something that may not be at fault.

Anyone fitted a K&N and had the same issues? If the MAF does turn out to be faulty, should I get rid of the K&N as well? Or is the filter likely to have shed its excess oil after a couple of thousand miles and do no harm to a replacement MAF?

James

[WW_VRS]

Excess oil could have caused damage.

Does the car seem to smoke a lot as well, as that tends to be related to the MAF a fair bit as well.

Power wise you'd be down a bit but it might have 'gone' over time - this is what happened to me and I didnt notice at first, only when the new one was fitted did I feel how the car should have been driving

[VRStu]

At 77k I would think a new MAF would be a good investment.

I don't think people place enough importance on these items and would welcome the idea that they were placed rountinely at say 60k.

[Spanner]

So, having too much oil in the car is going to going to damage the engine?

In the last week or so mines been feeling like it doesnt accelerate quite as quickly as it should be. Everything is fine though idles fine starts fine, engines seems a bit noisier though.

So was thinking of looking at replace any sensors i.e the MAF just to help keep it going.

[Windy]

Originally Posted by WW_VRS

Excess oil could have caused damage.

Does the car seem to smoke a lot as well, as that tends to be related to the MAF a fair bit as well.

Power wise you'd be down a bit but it might have 'gone' over time - this is what happened to me and I didnt notice at first, only when the new one was fitted did I feel how the car should have been driving

I thinks excess oil on the air filter getting drawn in the engine, and contaminating the MAF on its way to the engine

[mannyo]

Yes, its the oil sticking to maf from the K&N filter as it gets drawn into the intake system. This affects all the readings that the ECU gets and usually results in lots of smoke and not much power.

[WW_VRS]

sorry yeah I meant excess oil on the filter (as the oil is what's used to grab the dirt out of the air stream effectively).

That said overfilling the engine oil system isn't a great plan either, but that's a different question I should have been clearer in my original response

[James_H]

Hi, thanks for the responses. I have tried looking for smoke but can't say there appears to be a lot.

I have a can of IPA so giving the MAF a clean sometime won't do any harm and could give some benefit, although maybe only temporary..

[Chris GB]

Are the MAF sensors cleanable on the Fabia? The MR2 has a hot wire system that you can clean with carb cleaner. The Omega seems visually to have a electropolymer film element which would not fare well with solvent.

Would be nice if I could just pop the MAF out and blast it with carb cleaner just for the knowing it is clean.

Chris

[thephm]

Originally Posted by James_H

I have an Octy PD130 and fitted a K&N panel filter to it instead of the usual OEM paper one. Performance of late seems fine most of the time but economy is noticeably poor. I can't get much more than low 40s mpg, sometimes only low 30s (urban but not stop start crawls). I don't know how reliable the dash indicator is but you can often see it sometimes shows reasonable mpg, sometimes very low pretty much the same conditions.
James

What are you comparing it to ... don't forget the winter MPG drop for diesel's - when did you last fill up. I've recently put a Green Panel filter in my PD 130 and it's MPG has risen (when I'm not using the lead foot )
Also check your tyre pressures.
All the MAF failures I've heard about result in loss of power not MPG.

[James_H]

I have heard of more MAF failures causing low power (including my last). But excessive smoke is a sign of overfulling, possibly from a MAF saying there's more air than there really is. That said, I'm not sure how much should be excessive smoke- but I don't seem to get much. Tyre pressures are ok. I'll have a close look for anything untoward under the bonnet this weekend.

[Spanner]

I'd suggest people look in the technical guides section as it details how to clean the maf sensor.

[cjb]

Certainly when my Audi TDI had a buggered MAF MPG was as good as ever but performance was flat. This *was* at about 75K miles though.

Simple test is to unplug it. If performance doesn't drop massively, it's screwed.

[James_H]

Note the subtle change to the title! Although in this case, a bit like squishing a mosquito, it's a good thing but with a bit of a mess left behind.

On Saturday, I took the MAF off and gave it a good clean. I thought I would also check to see what my intake is looking like. Removing the EGR revealed these nasties:







Nowhere near as bad as pictures I've seen of other cars, but it can't be efficient with all that crud in the intake. I didn't have the time or the inclination to clean up the entire intake but decided to do just the EGR while it was off:



I let it to dry overnight then put it all back together on Sunday, but now I get a permanent check engine light and the Emissions Workshop message. I gather that the EGR is now sticking, so I've probably done myself a favour by it being stuck shut, but I just have the annoying light, bleep and message, or potentially another problem.

The car still drives like it did before, no problems with power. I tried with the cleaned MAF disconnected and it was noticeably worse than normal. Connected again and economy doesn't seem too bad on the short test runs.

I was tempted to buy a VAG-COM anyway so almost certainly will now to help find out what's the issue (and disable the EGR, or the new one if I need it).

Oh and one tip - if anyone else tries to clean their intake parts, dont get the oily goo on your fingers. I still cant get my fingernails completely clean.

[faboka vrs]

Reading the start of the thread I think I may have the same problem as you. For the last 2 tanks of fuel I struggle to get more than 41mpg. Last tank lasted 310miles from fill up to fuel ligh coming on. Need to get vag-com out to log some readings from the maf and compare to past logs. Dont think I will be able to do it tonight but I'll try.

[bahnstormer vrs]

Reverting to the original question - K & N on PD130 - Have I killed my MAF?

There seem to be two conclusions I can make out in this thread;

1. If you are going to fit a K & N/Green Cotton/Pipercross or similar filter to your PD engine you should ensure that it is 'dry' i.e. 'not oiled'. If it is oiled from new then clean/degrease it before fitting.

2. The MAF sensor only seems to have a service life in the region of 65 - 80,000 miles regardless of other factors. We have a Golf 1.9 GT TDi (115bhp) in our Company fleet and had to repalce the MAF sensor on this after only 45,000 miles having used OE filters!

Am I on the right lines?

[faboka vrs]

Correct

[andy gtr]

I know im a newbie, but if you are going to use a preformance air filter I would use a dry type one as well. I have just come from the jap scene, and a large majority of owners use the Apexi type air filters. These are expensive but there filteration is 1st rate, along with increases air flow. I have heard of a few european cars using these air filter as you can order a universal fitting kit which can be adopted. Also cleaning them is very simple, all you need is compressed air.
check out this link.

Air Induction, one more time. - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

[James_H]

Interesting thread. It seems the oiled filters offer trivial airflow benefit in exchange for low filtration. Cleaning off the MAF-killing oil on an oiled filter would let even more dust through.

So if getting an aftermarket filter, it seems best to stay away from the oiled versions completely.

[andy gtr]

Thats right James, basically the best air filter are the dry type. I have used the Apexi and they are very very good. I took be a long time to decide, and a lot of research and this came out the best. They are expensive, but you also dont need to replace them.