Thread: 1994 4BD1T Garrett Turbo questions

Hi Steu,

Good to hear you got it on the road and sorry to hear about the turbo.

Have you tuned the engine up? I remember reading somewhere that the army ones are detuned and perform worse than a standard 300tdi until tuned up.

Also, with the turbine resistance, if you are testing for resistance by hand when the engine is off seem the bearing is an oil fed bush maybe it will have less resistance when the oil pump is pumping oil into it. Just a thought, I am far from an expert haha

Jimmy

Bin the turbo and put a better one on. TD04HL-19T is a much better option. Your 2256, although a tad small for real power gains, may still be a better option, particularly for low end power

Originally Posted by Jimmy93

Hi Steu,

Good to hear you got it on the road and sorry to hear about the turbo.

Have you tuned the engine up? I remember reading somewhere that the army ones are detuned and perform worse than a standard 300tdi until tuned up.

Also, with the turbine resistance, if you are testing for resistance by hand when the engine is off seem the bearing is an oil fed bush maybe it will have less resistance when the oil pump is pumping oil into it. Just a thought, I am far from an expert haha

Jimmy

The turbo 'bearings' (journals) seem the culprit as quite noisy- a kind of warbling high pitched sound replacing what should be boost and not evident at idle or revs while stationary, or when the engine is not under load.


Boost kind of makes itself known in a very half hearted way late in the rev range.


I had a civilian 6x6 years ago (prolly an IHI) and remember it as having definite boost- though somewhat cancelled out by the low ratio axles when on the road so I would have expected that this 3.54 setup would confer healthy legs for the engine/turbo setup to do its thing.

On that score- before the turbo decided to play up (it took about 20km in driving distance to deteriorate markedly)- the car sat on 130km/h with more in store so gearing/noise/engine rpm seems very good (four speed army box) for my purposes.

As Vern offers above, it would be better get a relevant turbo - the 6X6 Perentie turbo is for a different use and was never particularly suited to highway work it seems.

There are experts around (not me) who can give good advice

Originally Posted by 87County

As Vern offers above, it would be better get a relevant turbo - the 6X6 Perentie turbo is for a different use and was never particularly suited to highway work it seems.

There are experts around (not me) who can give good advice

yes of course that is good advice but I want it running just so as to state 'factory original 99.9%' at machinery. I have the future mods in mind, at present I need advice on present setup.

Spending $80 or so on a service kit for the original garrett compressor seems ok for the time being. Is the one I have listed above correct for the turbine in question? I'm checking is all.

I know the old 6x6 4BD1T turbo is pathetic in comparison to what it could be. Keep in mind that I am after good fuel economy and usable proper levels of torque and power at the end of the day- in that order. Competing with modern 4WD contraptions is not a priority. I already have have old OM612.963 and OM605.960 powered Benz diesels more than capable of showing any nismo or toy a healthy rear end which is amusing in its own right. My 130 is a different story. I like simple and tough and trouble free with good fuel economy. If I can keep the original Garrett setup I would. It just depends on its behaviour and the balance between revs and torque.

Where the exhaust housing fits to the centre, is there corrosion? I had a go at this on my old turbo and the bolts were seized so I cut them. Then I couldn't get the housing apart anyway. So I bought a new turbo. There is probably some techniques that will assist in getting it apart but I don't know how to do it! Good luck.

Im no turbo expert. However, the TB2518 was designed in the 80s at best. Surely there must be more advanced mechanically waste gated options.

A roller bearing turbo is supposed to be better.

I've learned that getting the best option is not simply about more fuel. More fuel doesn't always mean a better performance in terms of the balance of what you want. For example with my roller bearing turbo, I wanted a good power, economy, not too much heat, less noise. Winding the fuel screw back a touch gave a better balance for me.

I wouldn't bin the old turbo, but I would buy a updated T2 one. A turbo for a CA18DET is an option being a T28. A GT2560 is the roller bearing option. I would buy a refurb kit and put the old one on the shelf in case you need it.

Its normal for a bit of sideways play at the compressor end so long as its not enough to for the compressor wheel to hit the housing. In operation oil pressure and rotation remove that play (bad description but hopefully you get the idea).

First things first, do you have a boost gauge fitted and if so are you getting any?
Does the engine have the boost compensator on the back of the injection pump? My understanding is that if that isn't seeing sufficient boost it will prevent the additional fuel required to create more boost.

If you don't have that compensator then I'd expect you'd be seeing lots of black smoke with throttle if you've got a boost problem.

Do you have an EGT gauge fitted?

On the Garrett turbo's I've played with, the exhaust housing comes off after you remove the bolts between the center housing and the exhaust housing. Been a while, but from memory there are a couple of semi-circular plates that the bolts go through that clamp it to the center housing. May require a slight tap to get it off but nothing major.

I put a bearing and seal kit in mine before fitting it and its still fine after around 50K Kms, but doesn't sound like that's your issue. If it IS turbo, it's sounding more like the turbine wheel has an issue.

Steve