Chimaera mass air flow cleaning
Discussion
Whilst investigating idle problems on my recently purchased 95 Chimaera, I replaced my vacuum advance line which was missing and also found that my mass air flow (MAF) unit was loose at the clips to the base of the unit plus both jubilee clips that connect the hose to the plenum were loose too. Great I thought, that'll help but now let's check the state of the MAF while I'm here... Wow, that thing was filthy. Didn't look too dirty on the outside but inside there was corrosion to the surface of the aluminium plus the grill was black with thick tar and bits of small debris stuck to it.
Interestingly, I didn't see much information on the forums about cleaning a 5AM Lucas MAF so I thought I'd post a few pictures of the cleaned up unit for reference. Yes, I should have taken some before shots too but I wasn't sure the detail would show up on my mobile phone.
Cleaned unit
Intake side with end flange removed
Outlet side with end flange removed
Main body stripped showing the MAF sensor wires
I ended up stripping down the MAF in terms of removing both end flanges which took a simple torx driver to remove 4 screws at either end. There was a paper gasket between each face which came away easily and which I reused. Paper towels and some fine wet and dry removed the corrosion from the aluminium faces and then a final wipe with cotton cloth wetted with solvent (brake cleaner) removed any grease or oil from the surface. Since the unit was stripped I could see the delicate MAF sensor wires down a straight through hole. The entrance had some debris that I carefully removed with a wetted cotton bud. Carefully does it and then I cleaned the sensor wires with some Wynns EGR cleaner which is OK for MAF cleaning too. Some oil definitely came off the wires and I gave them a few blasts from each direction down the hole until no more residue came away. I then let it dry out overnight and then rebuilt the unit. It was obvious what went where so the rebuild was easy.
Close up of the cleaned MAF wires
Back into the car and everything tighten up. Now the idle is a lot smoother, about 100 rpm lower and the throttle response is better too. Well worth the effort.
How often do people clean these? Every couple of years?
Interestingly, I didn't see much information on the forums about cleaning a 5AM Lucas MAF so I thought I'd post a few pictures of the cleaned up unit for reference. Yes, I should have taken some before shots too but I wasn't sure the detail would show up on my mobile phone.
Cleaned unit
Intake side with end flange removed
Outlet side with end flange removed
Main body stripped showing the MAF sensor wires
I ended up stripping down the MAF in terms of removing both end flanges which took a simple torx driver to remove 4 screws at either end. There was a paper gasket between each face which came away easily and which I reused. Paper towels and some fine wet and dry removed the corrosion from the aluminium faces and then a final wipe with cotton cloth wetted with solvent (brake cleaner) removed any grease or oil from the surface. Since the unit was stripped I could see the delicate MAF sensor wires down a straight through hole. The entrance had some debris that I carefully removed with a wetted cotton bud. Carefully does it and then I cleaned the sensor wires with some Wynns EGR cleaner which is OK for MAF cleaning too. Some oil definitely came off the wires and I gave them a few blasts from each direction down the hole until no more residue came away. I then let it dry out overnight and then rebuilt the unit. It was obvious what went where so the rebuild was easy.
Close up of the cleaned MAF wires
Back into the car and everything tighten up. Now the idle is a lot smoother, about 100 rpm lower and the throttle response is better too. Well worth the effort.
How often do people clean these? Every couple of years?
2000 year car with 60,000 miles when mine was removed for Mbe. Other than the mesh slightly pulling away from the edge in one place it was clean as a whistle.
That suggests blow back from the engine somehow. Flooded then a terrible back fire could cause this effect possibly!
Does your elbow pipe show similar deposits.
If a car has been stood for a few years I can see corrosion like this taking hold very quickly.
That suggests blow back from the engine somehow. Flooded then a terrible back fire could cause this effect possibly!
Does your elbow pipe show similar deposits.
If a car has been stood for a few years I can see corrosion like this taking hold very quickly.
The corrosion on the alloy surfaces indicates a lack of use, maybe during the wet months and it lived outside? All the dirt could also point to someone running it without an air filter? Perhaps as ClassicChim has said it has been stood for a while sometime in its life?
Cleaning the sensor wires probably helped but for anyone doing this, you must not use a screwdriver/wire rod or other object to do this as they are delicate and you run the risk of damaging them. A cleaning spray is all you need to do.
Cleaning the sensor wires probably helped but for anyone doing this, you must not use a screwdriver/wire rod or other object to do this as they are delicate and you run the risk of damaging them. A cleaning spray is all you need to do.
Yes the previous owner was a farmer and I got the impression the car was stored for long periods of time. There are other signs of moisture damage about the car - all minor - mildew smelling carpets, heavy water stains to the windows and tarnishing to the backs of the instruments under the dash. All signs the car was opened up to the elements for a while. Chassis is very good though and was the main reason I took the plunge with this car.
The other elements of the tubing all looks in good condition and clean. The air filter is there but I’ll change it for a new one as the condition isn’t great.
The other elements of the tubing all looks in good condition and clean. The air filter is there but I’ll change it for a new one as the condition isn’t great.
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