Thread: Is this a MAF problem

Jon, check all th obvious like turbo hose leaks and delaminations etc, also have a very close look at the wastegate actuator hose as they can cause symptoms such as this if they have a split or are leaking at the clamps.

Sounds very like an overboost situation to me.

JC

G'day Jon,

Agree with Justin there. Sounds to me more like a loss of airflow in the system. If all the hoses are attached and tight then I'd be thinking one of the hoses may have delaminated or have a tear. I know of owners who have replaced their LR original air hoses with silicon equivalents for this reason.

TD5's in D2s and Deefers are known to do this on occasion. Seems to be a little more common in D2s (possibly due to their different tune mapping - don't know).

I do remember reading on a forum somewhere about an owner having an intercooler hose delaminate causing these symptoms. The hole only opened up when the walls of the hose deformed a little and lifted the material. You may be able to hear this sort of failure as a shrill whistle. It is noticeably different to the turbo spinning up.

All is usually well on the flat when no turbo assistance is really necessary but becomes painfully obvious as soon as some boost is required such as uphill or under serious welly.

The wild swings in MAF readings may indicate a slightly dodgy connection or may just be a symptom. Worth checking the connectors anyway.

Good luck in hunting down the culprit. Like Justin said. Start with the hoses.

Cheers,
Iain

Thanks guys.

Ive just been outside whilst theres a break in the rain.

All hoses are connected and no visible rips in them.

I took the air filter box off and I think Ive found the issue.

I didnt mention in my first post because I didnt think it was relevant, but it was heavy rain all day yesterday.

My air filter is damp all the way through and the inside of the air box has drops of condensation (?) in their.

The air filter was replaced last week so I know was good. Its now drying under the mrs' hair-dryer! Just about every fin is wet.

I guess every bit of moisture thats stuck on the filter is one less air void to feed the engine?


Assuming thats the problem... now to the cause???

The car has a Mantec "plastic jobby" snorkel on it, all the rest of the air ducting is standard and all looks to be intact. Im guessing its just sucked up so much damp air and the filter has done its job to the point where it was effectively clogged??

What do you reckon?

Thx
Jon

Well, Yep,

I'd say this would definitely cause your problems. Hard for an engine intake to breath through water. It's highly unlikely but what little mist may have actually been injested all the way through the intake and into the cylinders shouldn't be a problem. Will affect combustion and keep things running a little cooler but is not physically enough water to stress things like head fixings, etc.

As to how this happened, therein lies the mystery. If your RAI has one of those Mantec "top hat" thingies on it then it puzzles me a little. Although a decent intake draught could suck sufficient water up and under this to dampen your air filter. Not sure how you would go about testing and I don't know how waterproof or otherwise these Mantec creatures are. It is certainly possible given all the rain that some water may have got past a join in the plumbing along the way to the filter.

Some years back when I still had my D2 I injested some water similar to this through my Safari RAI and wet the air filter. It did have one of those "ram air" heads on it at the time (before I fitted a Donaldson pre-cleaner) and the rain was so heavy I couldn't see the bull bar from the drivers seat. It was sufficient to set up a puddle at the bottom of the air cleaner box that didn't quite make it out of the drain in the base. No ill effects, fortunately, other than a couple of misfire coughs which prompted me to check things when I stopped.

So, yes, prime candidate for your symptoms is the moist air filter.

I made sure the installers of my RAI used copious quantities of Sikaflex on all the joins to ensure its water-fastness if pressed by water over the bonnet scenarios. Harder to stop if it reaches the big hole at the top though

If yours has been installed with only light sealing or, g*d forbid, dry joins then with all the rain over that period it's possible some moisture did get in elsewhere than the main intake. I don't wish to alarm you. Most installations will maintain their water-fastness through 99% of normal circumstances. Prolonged exposure will try any system, no matter how scrupulous the sealing.

Like all preventative maintenance. It can't stop a part from failing though it will skew the odds against it.

Hope the filter dries soon and you can get it back into service.

Cheers,
Iain

Guys,
Had the filter back in late this afternoon (almost dry!!) and went for a bit of a drive.

Thankfully no problems.

I guess I'll get back home tomorrow and then think about looking closely at all joints in the air pipe-work.

I know the Mantec is on correctly, did that myself

Thanks for the assistance and pointers earlier today.

R
Jon

Originally Posted by Yorkshire_Jon

Guys

I know the Mantec is on correctly, did that myself


R
Jon

Jon, I will be up for a snorkel in the near future, like the look of the Mantec, it seems to fit on the vehicle in a more subtle way than the others, can you tell me if the Donaldson filter head will fit on it? Also, did you buy it from the UK, or Aus., cheers Bob.