Exhaust bag jack with turbo

[Ian H]

I've been reading a thread (not in here) where exhaust bags were discussed and the point was raised that you shouldn't use one with a turbo charged motor due to the back pressure causing a problem in the turbo itself.

Anyone here have a comment. Is it right or wrong ?

[old Jack]

Hi Ian,

The no exhaust jack on modern turbo Diesel engines goes back many years but since then engines have changed. Ironman advertise a Modern Tirbo Diesel Safe Exhaust Jack, http://www.ironman4x4.com/category-p...t/exhaust-jack

Although exhaust jacks appear to be quick and effortless to use, there is a number of precautions and limitations compared to other jacks.
1. Care must be taken to avoid sharp rock or under body parts such exhaust systems, wiring looms and fuel/brake lines that can either damage the bag or be damaged by the bag.
2. They lift from the body so the vehicle must be lifted to a greater height to get the wheels clear off the ground due to suspension droop.

For me a mechanical screw bottle jack, on a long base plate, placed directly underneath the suspension arm of the wheel you wish to lift is the safest, lightest and most reliable option.

https://www2.pajeroclub.com.au/forum/showpost.php?p=368191&postcount=24

OJ.

[Ian H]

Thanks for that OJ, it's exactly what I needed.

[NTBenny]

I have an exhaust jack but it also has provision to be inflated with a compressor. I'm interested to know how an exhaust jack could damage a turbo. I'm not convinced it would be but I'm open to discussion on the topic.

Benny.

[erad]

I think that the main concern is the increase in back pressure on the turbo. If you were running the engine flat out at max throttle, this could be a problem and cause the turbo to overheat, but at idle speeds, I cannot see any problem in the short term.

[nj swb]

I think that the main concern is the increase in back pressure on the turbo. If you were running the engine flat out at max throttle, this could be a problem and cause the turbo to overheat, but at idle speeds, I cannot see any problem in the short term.

I agree.

I believe the whole theory is based on false logic:

1. Back pressure for turbo engines is bad.
2. Exhaust jack creates back pressure in exhaust.
3. Therefore, exhaust jack is bad for turbo engines.

As erad noted, back pressure is an issue for engines attempting to produce peak power / torque, not for an engine at or near idle.

I guess a modern diesel with closed DPF and pressure sensors could be confused by increased pressure readings in the exhaust? I can see that it might throw a code, but cause damage? Inconvenience, yes - a DPF initiated limp-mode that can't be cleared on the track could be a significant problem. If you're driving remote without the means to clear such limp modes you have bigger issues to worry about than an exhaust jack.