Under bonnet fuel filter and performance?

[wanted Member Find all posts View Profile Close wanted]

Hi All,

Recently had the 40k service done. Got the service people to change the under bonnet fuel filter at my cost, they were reluctant like not required till the light comes on and on and on.....

Post service the vehicle runs better, more responsive and while trying to find and answer as to why (not that I was not happy that it was running better and clearly more responsive) found the this thread where the use of winter fuel is known to clog the filter especially in UK? Apparently like every where else in the world everyone got informed but hey who cares about people down under? As we are coming up to winter again this may cause problem again.

https://www.landcruiserclub.net/comm...-power.136774/

"The new D-4D engines (across the Toyota range) have a new type of fuel filter which gets clogged by the additives in the UK winter fuel. The solution to replace the filter housing with a heated housing to heat the fuel. There is also a heat exchanger being installed at the tank which heats the out-coming fuel with hot return fuel from the engine."

Anyone else experience such a change or similar change? Mind you the servo that I fill from has winter diesel for a few months in winter.

TIA.

[nudgebar Member Find all posts View Profile Close nudgebar]

I know for certain that the factory filter is rated at 10 microns , so i presume that any particles slightly larger than that or even increased viscosity may reduce fuel flow. however the filter heads have a pressure sensor built in , so any pressure loss should bring up the " clogged filter " warning light.
I presume that once fuel goes though the main filter and arrives at the pump it will be warm enough to flow freely. There is also a fuel cooler adjacent to the commonrail swarf filter which allows unused fuel to be cooled down then sent back to the pump. there are clear diagrams on the Russian Toyota site which show how it all works

[wanted Member Find all posts View Profile Close wanted]

As noted in the post from another forum, the issues has been due to an additive in the winter fuel. So there must be some additive that is causing the filter performance to degrade. It does not come to a complete halt but seems to slow things down.

I can clearly feel the vehicle to be lot more responsive than before service. Going to add a pre-filter soon so lets see how that works out!

[GEEEXL Member Find all posts View Profile Close GEEEXL]

you have your air filter changed as well ??

16 to 18 + THOUSAND psi in the fuel rail mate, think your barking up the wrong tree IMHO

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

you have your air filter changed as well ??

16 to 18 + THOUSAND psi in the fuel rail mate, think your barking up the wrong tree IMHO

Those pressures come after the filter, the filer would go off like a bomb if you tried to put 18000psi through it .

Unlikely to be the filter causing issues, the filter warning light comes on long before any performance issues and it would also just by pass if it was really blocked (assuming it has a bypass?)

[GEEEXL Member Find all posts View Profile Close GEEEXL]

Those pressures come after the filter, the filer would go off like a bomb if you tried to put 18000psi through it .

Unlikely to be the filter causing issues, the filter warning light comes on long before any performance issues and it would also just by pass if it was really blocked (assuming it has a bypass?)

Yep that why i said "in the fuel rail"

just pointing out that "after" the filter there is some serious pressure and the filter is very unlikely to cause any issue

blocked air filter being changed on the other hand will

G

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

I've had a similar experience with a blocked diesel water separator as I'd left it in for too long. I was told that the filter paper hardens up and restricts flow so more engine power is required to drive the fuel pump to suck the fuel through hence the power loss.

[wanted Member Find all posts View Profile Close wanted]

OK on second thought this may not be very relevant to lot of people as majority do not use winter fuel. So apologies to those who may be a bit confused.

The Air filter was not changed at the 40k service. So from all items that got changed on the 40k service included the under bonnet filter that I got changed. I cannot think of anything else that could cause the vehicle to run a bit better.

As mentioned the high pressure is only after the fuel injection pump. And if sufficient fuel is not being fed through there will be some performance lag. Now this could be little that is not picked by the system as a blockage that it reports. I am not an expert so cannot say how the system works.

Bottom line if you have used winter fuel there might be some benefit in changing the under bonnet filter as it 'may' give the vehicle some performance boost.

Good luck.

[Walshy64 Lurker Find all posts View Profile Close Walshy64]

The additive you will find is cool flow improver. It helps the diesel flow in cold conditions. When this fuel is mixed with moisture it forms a film on the filter media thus blocking the filter. Especially if you are using bio fuel.

[wanted Member Find all posts View Profile Close wanted]

Welcome Walshy64! Join the fun!

Humm, that is good to know. Is there a way out to avoid that film being formed, like a heated filter, heated pre-filter? Since we get the winter Diesel around ACT there is not much choice. I think most servos have winter fuel. So may watch the performance during and post winter to see if there was any issue. But generally this is only for areas that get the winter fuel so everyone else can relax.

Cheers

[GEEEXL Member Find all posts View Profile Close GEEEXL]

40 thou service include valve clearance by any chance?

[wanted Member Find all posts View Profile Close wanted]

Yes, 40K has valve clearance?

[GEEEXL Member Find all posts View Profile Close GEEEXL]

mate 40k seems to have valve clearance diff oils etc & even just putting air in the tyre's is going to give you a change in the "feel" of the car fuel filter . . . nnnaaaahhhh

[wanted Member Find all posts View Profile Close wanted]

I was hoping that you will spring a surprise when you asked about the valve clearance at 40K! So what was your point to ask about the valve clearance?

By the way the vehicle gets tyre pressure checked every 2-3 weeks. Won't wait to hit the service interval to do that.

So of all what I have said is on the back of the information that I found regarding the winter fuel and the filter issue that is apparently circulated through Toyota bulletins in UK. So what you are saying is that nothing in the 40k service could have contribute to the improvement. Well that is what could be relevant to your case not mine! I feel improvements and went looking for answers so I can that more often! Thanks.

[GEEEXL Member Find all posts View Profile Close GEEEXL]

I was hoping that you will spring a surprise when you asked about the valve clearance at 40K! So what was your point to ask about the valve clearance?

By the way the vehicle gets tyre pressure checked every 2-3 weeks. Won't wait to hit the service interval to do that.

So of all what I have said is on the back of the information that I found regarding the winter fuel and the filter issue that is apparently circulated through Toyota bulletins in UK. So what you are saying is that nothing in the 40k service could have contribute to the improvement. Well that is what could be relevant to your case not mine! I feel improvements and went looking for answers so I can that more often! Thanks.

Sorry mate

I have just been posting in sneaky micorsecond breaks at work so short sharp posts - you have had mechanical adjustments (valve clearance) and fluid changes - IMHO your increased pep is from that, not your fuel filter

ive been wrong about 1574 time this week already though