Turbos

[roosmith]

I've been investigating the Bongo this morning and think that my sluggishness could be turbo related. In fact I think I've solved it but inadvertently in a rookie kind of a way. I took it for a test run with the passenger seat up and couldn't see any movement from the actuator. So I took the heat shield off and tried moving it with pliers and there was some movement. How much is there supposed to be though? It's only a few millimetres really. On taking the shield off I noticed though I also noticed the lower half of the turbo is quite oily. On top of that the bottom pipe was loose. I pushed the pipe back on and tightened and took it for a test run and I'm fairly sure it's fixed (you know when you can't work out whether you're imagining it!) . Of course I now don't know if I freed the actuator by moving it with pliers and applying plusgas or the pipe was the issue. What does that pipe do? Also would the oil have caused the pipe to slip or did the loose pipe cause th oil leak?



I'm going to go and tow the caravan as a proper test as that was awful when I had the issue, I'll know 100% then if it's fixed but I'd like to understand what could be causing what and how to prevent it if possible.

Thanks as always

[Northern Bongolow]

the oil is from the crank case breather, the little pipe off the rocker cover that goes into the large air pipe at the rear of the head, this oil is usually from the valve stem seals, or the piston rings. i took this rocker cover pipe off mine and let it go to atmosphere like an old mini. this helps the engine grab clean air via the filter and gives a better burn. the oil will work through the pipework to the turbo and on through the intercooler (they can get filled up) then show at the air inlet manifold bend, then it starts to restrict the air inlet manifold by turning to heavy carbon deposits.
the only real thing to do is to clean all the pipes out.

the clip you mentioned can come loose as its the first joint after the air pressure has been boosted in the turbo, ive had it a few times when it blows off completely in heavy trucks.

this can be helped by using the correct or above spec engine oil to keep the internals (rings, valves) clean, good fuel is also important, it maybe would benefit from a good fuel side cleaner (pump, injectors,) and a good egr, turbo cleaner.

[roosmith]

Thanks Northern, good information as always.

I'll do some house keeping then and see what happens. It happened while towing the caravan, so that fits it was under load and would have been working hard. Always sad to here that what I'm seeing is signs of wear. You know it's happening of course, you just wish it wasn't. Funny you should say about the fuel as well, as I run a veg oil mix, so do sometimes suffer. I'd already made up my mind that when my current batch of oil was gone, to stop using it.

[roosmith]

Oh and that did sort it, it towed the caravan lovely again.

[scanner]

If by the bottom pipe you mean the oily large bore one that comes off the scroll part of the turbo - then what is does is feed the air pressurised by the turbo to the inlet manifold. If that isn't tightly sealed and in place all your turbo is doing is increasing air pressure under the engine cover.

[roosmith]

Thanks Scanner, I can't make out where it goes but that sounds like it and would fit with no power.

[Northern Bongolow]

it goes to the intercooler, this cools the hot air which has left the turbo under pressure, if this warm less dense air went into the inlet manifold it would give a poor bang, so it is cooled to make it denser so it gives a better bang in the bore.

the actuator rod should move more than a few mm, it sounds like it needs a good clean out and de-coke, remove the pipes either side of the turbo and get a good quality turbo cleaner, then lube the pivot / rod .

this sort of thing works wonders. click on the video link.

http://www.wynns.eu/product/turbo-cleaner/