diesel rattle in D4D Prado

[mardo Lurker Find all posts View Profile Close mardo]

Did a bit of an experiment over the last couple of weeks, I ran the Prado with out fuel additives for one tank load (~150ltrs) and sure enough, on cold mornings she knocked like a Sherman tank and even when she was at operating temperature I could still detect a slight knock in some circumstances.

Next fill up, I used an additive (Redline 85 plus). After about 20 -30 kms of driving, she purred like a content cat. Even recently with the bloody cold Melbourne mornings, not a hint of knock, just a subdued thrum of the engine and a bit of turbo whistle to go with it. It has the same engine sound like your coasting down a hill and the engine is revving up a bit because of the transmission has kicked down a gear.

This just reconfirms my thoughts that our lower quality diesel fuel doesn't agree with the Prado's fuel management settings. I hypothesizing that as the injectors 'aged', ie. close to 10,000 km, there might be enough wear and/or fouling of the injector tips that compound the problem and pushing it past the threshold of the software settings to eliminate knock.

Has anyone else had the same experience with additives (they need to be centane improver types not just cleaners) where the knock is eliminated?

I would still prefer a Toyota fix to this, we shouldn't need to add any fuel additives to get the basics right for engine running, ie. no engine knocking! The engine should be tuned to deal with our fuel quality, good or bad.

cheers
Mardo

[martybuzz Junior Member Find all posts View Profile Close martybuzz]

Thanks for the heads up Mardo. I will try this additive when I refill with 100% diesel. Is it readily available?

[Hornet Junior Member Find all posts View Profile Close Hornet]

Hi Mardo,
All major fuel companies in Australia comply with the minimum requirement for cetane index/number in diesel fuel that is not lower than what is recommended by Toyota.
Adding additives certainly improve the quality of diesel fuel, but is not a requirement (nothing in Prado's manual), meaning that D4D engine should work just fine on all diesel fuels available in Oz.

Martybuzz: I think Toyota manual refers to the use of bio diesel with the maximum of 5%, so not so sure about 50/50 mix you have mentioned before
But in saying that, Toyota should come up with the problem identified first and then with the fix/solution. As someone posted earlier, replacing 2 or all injectors is only a part of the problem as it doesn't recognise the cause of the rattle.
Will see what the come up with.
Cheers,
Hornet

[mardo Lurker Find all posts View Profile Close mardo]

Hi Hornet,

I hear what your saying about the published specs for our fuel quality in Australia and Toyota's engine requirements being met should mean we have no issues. However the reality is something is not meshing.

I can only base my statement on facts that are at hand,
1. We have some D-4D engines knocking when cold.
2. Mine started happening (and many others) when the engine was close to 10,000 klm old
3. My engine knocking is completely resolved when I add a fuel improver

What I don’t know is, when Toyota finally decided to introduce the D-4D engine, under what testing protocol did they employ. Did they ensure it was based on a worst case acceptance criteria, that is,

1. did they test an engine that had already done a 7000+ klm on Australian fuel?
2. did they perform the test in cold temperatures?
3. did they consider the inherent variability of cetane ratings of diesel fuel coming out of refineries and choose the lower end of the scale?

I don’t know!

What I do know is that what ever protocol they employed to validate the use of the D-4D engine in Australia its fallen short somewhere. Even the mighty Toyota with the best manufacturing quality system in world can get it wrong. There wouldn't be >18,000 hits on this topic if they got it right.

Of course, the other variable in this issue is that the oil companies are pulling the wool over our eyes and the diesel fuel falls well below the minimum specs they state. I know of no independent entity that can verify the cetane ratings of the diesel fuel they sell to the general public.

I cant change the engine software mapping as to alter the state of tune of the engine, but one parameter I can change that can influence the engine knocking is the fuel quality with an additive. When you do the maths, either the engine tuning stuffed or our Aussie fuel is stuffed.

Cheers
Mardo

[Big Fella Senior Member Find all posts View Profile Close Big Fella]

Mardo,

I have bought the Red Line 85 today $17.00 I have the tesh specs as well for it. I was wondering what dosage rate at you using on your car? There are several different rates to use. I'm just a tad confused (not hard to do) as I am going to fill up on Friday. Do you add before or after filling up? And how is it able to treat both tanks of fuel?

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

This is a copy of my post on page 6 of this thread

he link below covers a response by local dealership and also by Toyota Australia re a letter I wrote regarding dealership using an additive for an "on car diesel fuel injection service"

Whilst the dealership said in their opinion the additional service would not reduce any new car warranty provisions Toyota Australia were most adamant that any damage caused by fuel oils and fluids other than what is in their booklets would not be covered by new car warranty.

http://www.pradopoint.com/viewtopic.php?p=51657#51657

As stated in the link Toyota Australia were adamant that any damage caused by fuel and fluids (additives) not specified in their owner would not be covered by their new car warranty.

I am still awaiting a response from local dealer , as I have been away for a month , so it will be interesting to see there respose after they see Toyota's letter.

Also in above link I mentioned the following

The only part I can find in the owners manual (p 228)that relates to above is that the diesel should have a cetane number of 50 or higher,

I contacted Caltex and they said the australian standard was 46 and that on occasions their level was 50 but always above the 46.
Contacted BP and they said their level was always above 50.

I use BP exclusively .

Not sure if the additives and /or say use of Caltex ,or other fuel ,when the cetane is below the 50 mark could be the cause of the rattle but thought I would throw this in

[mardo Lurker Find all posts View Profile Close mardo]

Hi Big Fella,

it wont be cheap, but to get the full benefit you'll need 2 bottles. 1 per 90 ltr portion. I then alternate to 1 bottle for the subsequent fill, then back to 2 bottles. Works for me.

I always put the additive in first before the fuel to ensure thorough mixing during the fill. I put the first bottle in at the beginning, then stop filling momentarily a little after the 90 ltr mark, then the second bottle goes in and I finish the fill. This might be over the top but ensures you have additives in both tanks. I'm also thinking that you might be able to put both bottles in at the one go and let the recirculation of the fuel between the two tanks and high pressure fuel pump do the mixing, I but I need to investigate further on how our dual tanks system is set up first and the understand the return flowrate of fuel from the main high pressure pump to determine mixing rates.


Pedro,

I wouldn't be too concerned about warrantly issues from additives. Toyota dealers put an el-cheapo additive at service times for some customers and even if there was a fuel pump/injector failure they wouldn't have enough cognitive ability between the lot of them to prove if was the additive that was the root cause or something else.

Cheers
Mardo

[IRON-PAWW Avid PP Poster! Find all posts View Profile Close IRON-PAWW]

No need to apologize for a long post Drummo. That's good work letting Toyota know how widespread the problem is. I'm sure they must already know but are putting up a brave face in front of customers. One of the good things about forums like this is that they act like a kind of petition. Everyone who has the problem writes in and it adds to an irrefutable list of occurrences of a growing problem. Sooner or later the problem must be recognised at some level. Add to that the fact that I, and many others consider this forum reputable (no Fragwits). We are ordinary owners simply reporting on problems we are having. No doubt, Toyota reps have already gone through the thread several times. Another complete listing of reported incidents, nicely printed for easy reading is a good Idea. Keep the reports coming!

As Mav says, I think I'm heading down this path too. Only ever used BP Ultimate. Knock is there, but not too bad generally yet. Just that one day of bad knock so far.

[masso Senior Member Find all posts View Profile Close masso]

Picked mine up from Dealer last night. They replaced ONE injector ..said it was faulty. They confirmed NO extended warranty and NO other engine damage caused. I attach copy of questions and workshop ticket where they tested injectors. All a bit too technical for me i am afraid!

Started car this morning. No Rattle. All seems back to normal. Still cant fathom why it took 30000k to appear FAULTY tho.. certainly doesnt fill one with confidence. Dealer SUPERVISOR said it was first one he had seen at that dealership... which was #$%^& as they replaced two injectors on one the week before. I really dont think they give a toss... just do what they have to do to stop the noise, then get you out of their shop.

[mav Addicted PP Member Find all posts View Profile Close mav]

Picked mine up from Dealer last night. They replaced ONE injector ..said it was faulty.

Well by the look of the results I am guessing that they replaced number 4 injector and I reckon you can expect number 1 injector to start making the rattle soon. Number one must be close to the tolerance limit I would think.

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

Picked mine up from Dealer last night. They replaced ONE injector ..said it was faulty.

Well by the look of the results I am guessing that they replaced number 4 injector and I reckon you can expect number 1 injector to start making the rattle soon. Number one must be close to the tolerance limit I would think.

Hi Chaps,
The test refered to on the test sheet is an injector backleakage test within 10% is the norm for Bosch and Delphi injectors but I would need to check the manual for the toyota tolerances a bit tied up at present.

Strewth this thread is getting long but well worthwile.

[ades Junior Member Find all posts View Profile Close ades]

A couple of things I learned recently from Toyota.

They didn't tell me when I bought the Prado that it does't automatically come with "roadside assistance".

Keep that in mind if you're heading off on a big trip and you're assuming that it comes automatically with your new high priced Prado.

Second one they don't advertise is that you can purchase 'extended warranty' from Toyota.

I was planning to keep my car for 5 years and it only comes with the 3 year warranty.

Because my car is exhibiting the death rattles (something I'm planning to attack with the dealer at the 40k service coming up shortly), I'm definitely going to take the Toyota option and pay to extend the warranty.

Worth considering if the injector problem is ongoing.

Drummo wrote a great report. My car is from the same dealer.

It'll be interesting to see how the dealer handles it.

[Daz Senior Member Find all posts View Profile Close Daz]

Some other drivers having same issue.

http://www.motorsm.com/complaints/updat ... p?aid=2345

[lawrance Senior Member Find all posts View Profile Close lawrance]

Just got a theory on this rattle in the cold mornings - are the folks who are experiencing this not allowing the glow plugs to warm up fully before cranking the engine over?

Most modern day diesels these days, although equipped with glow plugs, can fire up first go without waiting for the glow plugs to get up to temp.

I'm wondering if there's any difference to the problem by simply allowing the glow plugs to get fully warmed up, i.e. glow indicator extinguishes from the dash before the engine is cranked over....

[martybuzz Junior Member Find all posts View Profile Close martybuzz]

Just got a theory on this rattle in the cold mornings - are the folks who are experiencing this not allowing the glow plugs to warm up fully before cranking the engine over?

Most modern day diesels these days, although equipped with glow plugs, can fire up first go without waiting for the glow plugs to get up to temp.

I'm wondering if there's any difference to the problem by simply allowing the glow plugs to get fully warmed up, i.e. glow indicator extinguishes from the dash before the engine is cranked over....

The Glow Plug light goes off as soon as you tun the ignition on! Which I think is the same with all common rail diesels.

I think we've all just about worked it out that it's a combination of fuel and firmware on the D4D.