I need a new Mass Airflow Sensor for my 94 960 sedan. It runs very well generally but has had almost a valve chattering sound for long time under a very light load, similar to the sound in the old days of running too low octane fuel. My indy Volvo mechanic cleaned the MAF while he was making other repairs to my car recently, and this problem was all but eliminated, albeit only for a few days. So I want to try a new MAF and don't want to spend $200+. I've looked around checked prices and found a couple of NEW units for sale for between about $75 and $87 plus a rebuilt one for about $73 + $33 core charge, which I'm fine with the core charge.

There are 2 brands of new MAFs mentioned above for cheap compared to OEM. One is Walker which I know the Walker brand from Walker exhaust systems, then there's Spectra Premium which I've never heard of. Does anyone have experience with either of these brands of new not remanufactured MAFs? Also there's A1 Cardone remanufactured with the core charge. I'd like to try one of these three preferably a new one unless someone is convincing in explaining why not to use one of these 'cheap' new ones instead of a much more expensive Bosch OEM one.

Any comments from personal experience appreciated. Thanks.

 

I don't see how a MAFS could cause valve chattering.

As far new ones, I haven't heard good things about the cheap aftermarket ones. So far I get used ones.

 

So I thought this through and wanted to purchase a MAF sensor which didn't require a core charge and return of the existing sensor. I decided for the price, if the new MAF sensor worked well, then not only had I saved money but I would end up with a spare part and a good conscience that it wasn't wasted. I tried 2 different sensors one bad the next good, very good.

Perhaps against my better judgment and against the advice here I first ordered the cheapest aftermarket MAF they had in stock at Rockauto.com. It was a TPI brand with #MAF1068. This thing was a piece of junk. It started OK then began to idle rough after less then a minute. Then after driving some distance and coming to a stop sign, it idled rough again. After swapping back the original MAF the problems went away, so I wasted no time setting up a return. Got back most of my 60-couple dollars.

After returning it I shopped around, checked prices and availability at several places. Finally I bit the bullet and ordered the Walker 851-05858891 complete new MAF assembly from Rockauto.com. There is no core charge and so I get to keep the previous one which I confirmed works as it should.. I installed the most recent new MAF sensor the same day that it arrived and so far going on 3 weeks in service it's working perfectly. No change in performance, starting,fuel mileage etc. The price for the Walker was about $76 versus $95 + $35 core fee for a Cardone rebuilt OEM sensor. I would definitely recommend AGAINST the TPI brand MAF sensor and FOR the Walker brand MAF as a cheaper alternative to the OEM. Works great and if anything changes I'll post back.

 

This new MAFS eliminated your engine pinging (valve chatter)?

 

No it didn't. I was afraid you'd ask. I guess there's something else/worse going on with the valves. It's weird because it does it when I'm basically under a very light load on the engine like very light acceleration. If I give it more gas the pinging or chattering stops, until I let off and get back into a state or more or less coasting along or light pedal pressure. It's been doing this for a long time, never gets worse, doesn't smoke not even at startup. This is a mystery to me. Seriously thanks for asking.

 

Well, so, the valve chatter still there... is predetonation or really valve chatter?

Your mechanic obviously is not up to the task, but that is important distinction if you are to solve this. I had a 960 back when that had a valve chatter due to oil issues but that was at start up mainly, cured it with oil change.

Your problem is not that by the sound of it, but who knows? That's why you need to establish exactly what the noise is. May be you can add some octane booster to the fuel, see if that helps--it should if it is indeed 'pinging'... I assume you have tried high octane fuel already?

 

Lev, yes I have tried octane booster and running 93 octane premium fuel multiple tanks multiple times running octane booster and it never made any difference whatsoever. Thank you for your reply and input. It could be predetonation, I don't know. What are some factors that can contribute to that if that is what is happening?

When it does it, if I press firmly on the pedal to accelerate harder, not anything extreme at all, just more than gradually accelerating, it will stop doing it while the engine is under more of a load... always it will stop. Then just as quickly, after I let off the throttle and when I am very gently just driving along, i.e. coasting with a little throttle, it will do it. So unlike the situation where it pings when you accelerate with more pedal, mine does the opposite. If I am accelerating to get on the interstate highway, it does not do it ever. If you are giving it a half way decent amount of throttle, it does not do it. It's only when I'm driving gently which is most the time, that it will do it.

 

Hello. I'm probably way late on this topic.I just joined this forum. My two cents worth : I would stick to Bosch oem sensors for our vehicles. Yes,they are not cheap,but you will save yourself headaches down the road. Aftermarket is poison for anything electrical. Just as Toyota requires oem Denso for good reason,use Bosch
for Volvo electrical.

 

Bosch is fine for the MAFS, not so great for everything as a general rule. A lot of the current Bosch products are sub performers in these Volvos: I don't use it for plugs, wires, CPS, etc.

And to the OP's point, I can't see how a MAFS would cause valve chatter.

So, VA740, if the chatter does not change with higher octane, then it's not 'pinging' or predetonation (same thing)! I'd be curious to get another mechanic's opinion on this. There are several other possibilities, hard to say without being there. I am not an expert on the that 6 cyl motor, I'm into the B230F/T, and from those I can tell you I have had some weird noises but the 960 is quite different, more complicated... I had one awhile ago for a short time, it valve chattered due to oil issues-I don't think this is your case.

 

One important thing about these engines(and other similar ones) is oil density. If you don't use a thin enough oil the lifters will be dry and chatter, especially at startup when oil is thick. At idle, after it warms, oil pressure is lowest and they'll still chatter. Once you start to rev it, as you accelerate, oil pressure increases and feeds the lifters. Try going to a thinner synthetic and see if that makes a difference. Or, if 960's have an oil pickup tube like 940's, then it could be leaking around the seals. Had that happen to my 940 and had low oil pressure until I revved it. 230 redblocks have a port in front of the engine where you can hook up an oil pressure gauge to check that out. Not sure about 960 whiteblocks? And if it is an oil pressure problem, it could be the relief valve in the oil pump. Some 960 models had a plastic cap on the plunger which wore out - https://www.volvoclub.org.uk/faq/960...mORingProblems