To clean, or nto to clean? That is the question. (inlet/EGR on RHR engine)

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UNM

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My 407 2.0 HDi is at 185,000km. Havign had it a couple months and put over 1000km on it, I am about to do an oil change and am wondering if it is worth running a can of upper engine cleaner through to clean up the inlet side.

Obviously, I would do this prior to the oil change so I can clean any remains out along with the used oil. Our Subaru gets this done every 10,000km as a matter of course.

As I have no idea if it has ever been cleaned before, there is a high likelihood it is pretty filthy in there and I don't want to release a ton of deposits into the engine and on to the DPF.

Is it safe to do?
Would it likely make a difference?

I guess the alternative is to take off and manually clean the EGR and inlet manifold - presumably time consuming and requiring new gaskets.


Any advice from those with more experience would be appreciated.
 
All you would be doing is adding some expensive fuel if you dilute it in the tank. Diesels inject direct into the cylinders under very high pressure.

The Subaru has direct injection also (as do newer PSA petrol motors), and the solvent enters the air intake to keep oil crud from fouling the inlet valves - it washes them. It then burns away like petrol. A diesel is designed for a much less easily ignited fuel, and would not be happy with a dose of solvent.
 
I've run a solvent through my diesels from time to time to clean the intake of built up EGR gunk. It runs just fine and seems to be effective in cleaning.
I use Liqui Moly diesel intake cleaner. It appears to be mostly acetone with some other additives in a fancy can with a long nozzle.
It gets sprayed into the intake after the turbo, after the MAF, near the throttle plate while holding the RPM around 2-2500.

seasink said:
A diesel is designed for a much less easily ignited fuel, and would not be happy with a dose of solvent.
Click to expand...
 
If one pulls the hoses off the throttle body on a RHR gritty oil gunk/crud will be found, and the older the engine is the thicker is the build up. The gritty stuff comes from the EGR which is a device that deliberately causes exhaust gas to be redirected from the exhaust system and mixed with nice clean filtered air. The influence of this filthy gas is such that it affects the insides of hosing which is upwind from its entry point into the inlet manifold. Obviously, any reduction in intake air flow will not enhance performance and the problem can get to be so bad that, as in the case of a D9 HDi I recently bought, the head had to be removed by the PO in order to remove the built up crud. Am yet to try an upper cylinder cleaner but have fitted EGR restrictors as ordained by Peugeot according to a thread of several months ago. Having seen the substantial crud build up in a 400,000k D8 2.1 diesel I would expect that several, or more, cans would be needed to shift it, but I'd love to be proven wrong and would buy a box of that product. An 05 auto RHR 407 with an engine issue is to hand so I may remove the manifold to see just how bad it is after about 250,000k of no restrictor. Most likely the use of an inspection camera would enable you to accurately assess the worth of any can of spray tested.
 
To clean, or not to clean? That is the question. (inlet/EGR on RHR engine)

So far nobody is saying don't do it & a couple sugesting it is worthwhile. Will give itanother day or two then decide.
The EGR restrictor is planned for my next time off work in a couple weeks (hope weather will be better by then).

Oh, and someone at work has a pajero with about 260,000km which is now losing power - he has been told it is an expensive clean, with the manifold off the engine. Not sure if they were going to do a head removal too. He is deciding whether to trade in and go to a newer tow vehicle.
 
I have cleaned the intake on two diesel Volvos, finding the bituminous material to to be fairly difficult to remove. I would really doubt a spray in the intake would remove between 6-10 mm thick of material from this area, and what the consequences would be of it making its way through the engine to be expelled. These intakes were cleaned at approximately 110 000klm, and was done using various screwdrivers and other implements, and thinners as a solvent. Not fun.
 
I once cleaned the inlet manifold from a 1.6 hdi c4. Removed it and left it to soak in petrol overnight. By the morning the petrol looked like used oil and the the gunk was pretty much all gone.

I've heard of a 2 liter diesel having the spray cleaner used. It then cleaned out all the gunk which become a fuel. The car then revved it self well over the red line. Luckily this one was a manual and they were able to put it in top gear and dump the clutch to get it to turn off. Luckily no damage was done. But be careful, only spray a little at a time.
 
Grasshopper.
When engine is running well do not upset the Apple Cart
The engine is likely to fart
Take apart at your on peril
It is likely to make your efforts less than fruitful
 
Hi cav91, and others interested. Whilst in conversation with a knowledgeable and experienced Peugeot trained mechanic during a discussion about self-fueling diesels he told me of an almost new D9 HDi which would empty the sump, blow lots of smoke and rev at unbelievable speed. Peugeot in France took an interest and the removed engine was tested on a bench in Sydney where the RPM got to 13,500 without destructing. The problem was a faulty turbo lubrication seal which is why the sump had to be refilled after every event. I do believe that the engine was replaced under warranty and the engine went to France.
 
kelpiebat said:
Hi cav91, and others interested. Whilst in conversation with a knowledgeable and experienced Peugeot trained mechanic during a discussion about self-fueling diesels he told me of an almost new D9 HDi which would empty the sump, blow lots of smoke and rev at unbelievable speed. Peugeot in France took an interest and the removed engine was tested on a bench in Sydney where the RPM got to 13,500 without destructing. The problem was a faulty turbo lubrication seal which is why the sump had to be refilled after every event. I do believe that the engine was replaced under warranty and the engine went to France.
Click to expand...
Wow that's amazing. Those early hdis really are indestructible!
 
That youtube is fantastic and adds weight to the statement that when my mechanic friend first saw it happen to the 406 HDi the close by Fire Brigade vehicle turned up to put out the fire. The only way to shut it down before the sump empties is to starve the air supply. Apparently it used to be normal, and may still be, to fit fuel tankers with CO2 canisters that fed directly into the intake system to suffocate the engine and prevent a run away 'truck wreck with fire', on hot days when tank vapours were taken into the air inlet system due to tail-winds.
 
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