1994 850 MAF bad after cleaning K&N air filter

soulvoid1990 · Post by **soulvoid1990** » 10 Mar 2015, 14:17

So we're at it again..

As the title says, after I cleaned my K&N box filter, it tripped my MAF. The car doesn't want to hold an idle well, and stalls. When you give it a little throttle, it will help, but sounds choked. The typical MAF sensor signs.

The thing is, is very very intermediate. The car will run fine for an hour sometimes, others, it won't run for 30 seconds. I've tried cleaning the sensor with CRC MAF Cleaner from Autozone, but after 3 cans of it, I gave up. Is there possibly anything else I can do to get it clean, or is it possible that a drop of oil got on the sensor, and has created a fault or something? I am getting a CEL for the MAF, but that's it, no other codes. Another thing, when it doesn't seem to be running right, if I unplug the MAF, the car will run fine for about 5 mins, then just die completely.

Another troubling thing, is that I seem to have something in my oil, after replacing the O-rings in the oil sump. I wanna say it smells like gas, but I'm not 100% sure. It seems to me that it's bubbles. When the car isn't running, you can't see anything in the oil, or on the dipstick. It looks perfectly normal. However, if I check the dipstick while the car is running, or the oil cap even, it looks like the pictures below, a white substance. I haven't changed the oil since we did the o-rings (About 3 or 4k miles), so is it possible that it is something in the oil, like the RTV for the pan, or maybe the universal grease we used to hold the o-rings in place? I'm going to change my oil once I get the car running correctly, and hope I don't continue to have issues.

It's definitely not antifreeze, and there is no oil in the coolant tank. I haven't had any issues with the car other than this MAF issue. It's not burning any fluids, or losing anything. I used to lose about a quart of oil between oil changes, but that has actually stopped with the sump working correctly now. Also, on cold days, (Here in PA, it was below 0 for the longest time) it would take 2-3 cranks to get it to fire. When it was -30, it took me about 5 mins to get it to fire. When it's warmer like it's been though, it will fire within a few seconds, like it should. Is it possible that the MAF could have been going bad, and the oil from the filter set it off??

Let me know what you guys think, before I go throwing parts at it. I don't have a way to do a compression test, at least not for a while, just as a side note.

soulvoid1990 · Post by **soulvoid1990** » 10 Mar 2015, 14:29

I also wanna note that this is my first time clean the filter since I got it. I did not over oil it, and I made sure to follow the directions to a T.

I also tried the car with a regular filter, and no filter, but no go. (No, I didn't drive the car without the filter, just sat in the garage

Post by **abscate** » 10 Mar 2015, 20:02

I think you will have to bite the bullet and buy a new MAF. It sure seems to be indicated bad and fro others experiences the oiled filters are known to kill them

Post by **scot850** » 10 Mar 2015, 23:37

Interesting you say oiled filters kill MAF's. I've had a 93 850, 98 V70 XC and a 2000 V70R all running K&N filters and so far have had no issues that I've noticed. What problems would I expect to see?

Neil.

Post by **abscate** » 11 Mar 2015, 05:20

I've never used a KN so I have no first hand experience. I think there are a few anecdotes on this board about this, though. If MAF use hot wire as a an airvflow measurement, I can imagine how excess oil could foul them, if you don't follow the manf. Instructions carefully.

Post by **850 LPT** » 11 Mar 2015, 06:00

I think the key is not to over oil them. I had a K&N filter in my 850 for nearly 200k and never had a problem.

Post by **abscate** » 11 Mar 2015, 06:14

Tons of stuff on the web not worth repeating here. As usual, people will start a world war to defend their positions on this stuff.

Upshot..many people have used them for thousands of miles without problems, and over oiling seems to be the culprit if you do have a problem.

Post by **rspi** » 11 Mar 2015, 08:03

How old is the MAF? What brand is it? Did it get banged up at all?

I use the K&N and have serviced it without an issue.

There is a lot of other info in that thread, do you need any other help.

Post by **scot850** » 11 Mar 2015, 11:39

It could also be coincidental that the MAF may have failed, or even have a poor/dirty electrical connection. I think as the other guys have said, the over-oiling of a filter may be an issue that can cause a failure of the element in the MAF.

Assuming this is the original MAF for the car, it could be time to replace anyway. Don't know if you have any parts yards around that you could pull a used one from to try? They are usually fairly cheap and in the case of my local pick-n-pulls is returnable in 30 days for a credit (no cash refunds). I think I paid $10-20 for the last one I pulled.

What we have all forgotten to cover here is your other issue of the 'fluid' in your oil. Has the car been standing for a while in a cold climate? It is possibly condensation, and by using the car more or taking for a good run it may clear. I would suggest swapping the oil and then taking the car for a good run and then see if the issue returns.

Is your car a turbo or N/A? I may have missed the info in the thread, if so sorry!

There are a few ideas floating around in my 2 brain cells, but don't want to send you down a rabbit hole without more info on what we are working with.

Changing the 'O' rings in the oil pan shouldn't cause 'moisture/fluid' issues in itself as I can't think where it would come from if you don't think it is water/anti-freeze.

Another possibility could be leaking injectors causing fuel to drain down into your oil pan once the engine is off. Also this could cause rough running, with the assumption of it being a bad MAF. You should smell it and the oil will be noticeably thinner.

Let us know what we are working on with you, and we can dig deeper.

Never heard the issue of over-oiling of K&N filters causing an issue, but it is absolutely a possibility that I could see happening. It could be a case of more oil is better, but in this case it is not!

It is always good to get different opinions from opposite view-points as it serves as a reminder that we can all get complacent!

Neil.

soulvoid1990 · Post by **soulvoid1990** » 11 Mar 2015, 19:42

scot850 wrote:It could also be coincidental that the MAF may have failed, or even have a poor/dirty electrical connection. I think as the other guys have said, the over-oiling of a filter may be an issue that can cause a failure of the element in the MAF.

Assuming this is the original MAF for the car, it could be time to replace anyway. Don't know if you have any parts yards around that you could pull a used one from to try? They are usually fairly cheap and in the case of my local pick-n-pulls is returnable in 30 days for a credit (no cash refunds). I think I paid $10-20 for the last one I pulled.

What we have all forgotten to cover here is your other issue of the 'fluid' in your oil. Has the car been standing for a while in a cold climate? It is possibly condensation, and by using the car more or taking for a good run it may clear. I would suggest swapping the oil and then taking the car for a good run and then see if the issue returns.

Is your car a turbo or N/A? I may have missed the info in the thread, if so sorry!

There are a few ideas floating around in my 2 brain cells, but don't want to send you down a rabbit hole without more info on what we are working with.

Changing the 'O' rings in the oil pan shouldn't cause 'moisture/fluid' issues in itself as I can't think where it would come from if you don't think it is water/anti-freeze.

Another possibility could be leaking injectors causing fuel to drain down into your oil pan once the engine is off. Also this could cause rough running, with the assumption of it being a bad MAF. You should smell it and the oil will be noticeably thinner.

Let us know what we are working on with you, and we can dig deeper.

Never heard the issue of over-oiling of K&N filters causing an issue, but it is absolutely a possibility that I could see happening. It could be a case of more oil is better, but in this case it is not!

It is always good to get different opinions from opposite view-points as it serves as a reminder that we can all get complacent!

Neil.

It is the original MAF and the car has 242K miles, so I'm assuming it's just time to replace it. I've already ordered it and it should be here on Monday. Will post and update as soon as I get it in. I'm going to assume that I over oiled it, and the sensor was too old to handle it. Not a big deal, hahah. I'm going to order the Bosch one from rockauto.

As far as the oil issue. The car doesn't sit for long. On days that I can, I drive my girl friends Jeep. So sometimes it will sit for 2 or 3 days, then I drive it to work again. I have been letting the car idle a lot with the cold weather (about 15 mins on the below 0 days), and I only drive about 5-10 mins to work each day, and it's never above 40 mph. I do go to the store and stuff, but I only put about 50-60 miles a week on the car. This has been my routine for the past 3 months.

I used to drive 30-45 mins everyday, mixed with town, and mostly highway. (81 for anyone that is from PA). And I usually let the car warm up for about 5 or 10 mins depending on the weather. Have I been letting it idle for too long in the cold without driving it enough?

It is a non-turbo that we are talking about haha.

I read a few different threads where people have suggested that it could be injectors. It does idle rough a little rough once it warms up, and when I use the rear defrost or turn the fan on high, my idle drops about 100 rpms. Same with the high beams. Is there a way to test the injectors or any signs to look for? I have cleaned them by letting it soak in cleaner for about 20 mins about a year ago.

Thanks again!