Caterpillar 3126 No Turbo Boost Pressure

[katlen86]

I was driving my 2002 Beaver home and lost a lot of power and noticed I had 0 turbo boost pressure. Made it home but it was tough, I hope I didn't cause more damage by driving it that way. Checked the air filter it was fine, what else should I look for. I'm a rookie when it comes to diesel engines.

[wolfe10]

Two things to start with:

1. If you have an exhaust brake, VERIFY that the butterfly valve is not stuck shut. When was it last lubed? What brand is it?

2. Check "plumbing" between turbo and CAC and CAC and engine. Something as simple as a broken hose clamp could allow boost pressure to blow the hose off.

Brett

[katlen86]

Last lubed about 4000 miles ago, its 2002 Beaver Patriot

[katlen86]

I will check hoses this afternoon, have to pull bed out to get to engine. Exhaust brake was working coming down hills after I noticed no pressure.

[wolfe10]

The question on the exhaust brake is not whether it worked (butterfly closed) but, whether the butterfly completely opened when the exhaust brake was turned off.

[katlen86]

I'll check that too.

[desertdeals69]

When I broke a hose clamp on the cac hose the engine didn't have enough power to move the coach. The hose would just blow off. I would check the waste gate, maybe stuck open.

[katlen86]

The waste gate is that on the exhaust side of turbo and cac hose is were. The turbo has 2 steel tubes coming off it 1 at top and 1 at the bottom. Forgive but I'm a rookie on diesel engines.

[wolfe10]

Follow the hoses/steel tubes from turbo to CAC (looks like a radiator-- actually it is an air to air radiator) and from CAC to engine. Make sure the boots/hoses are in place and clamps tight.

Also, check that the exhaust brake butterfly moves freely (though the return spring is STRONG.

[katlen86]

I checked all hoses and clamps and checked wast gate all checked good. Should I replace turbo boost pressure sensor next or is there something else I should check? I appreciate all the help so far.

[Guest BillAdams]

I assume you have checked that the turbo itself is not the problem?

[katlen86]

To check the turbo itself I need to check to make sure it turns freely, what is the easiest way to do this. Remove the clamps on the exhast side or the boot on the other end. Also I failed to mention I have a check engine light on and a failure code zero turbo pressure code 100-36

[wolfe10]

You can access either the exhaust side of the turbo by removing the clamp to exhaust brake or exhaust pipe-- it is a little more work than removing the hose from the intake side.

But, if the hose is older, it may split as you pry it off.

Unless you are familiar with working on diesel, I would do the other checks first, as they do not require the same level of technical skill.

While the turbo could be at fault, with boost going from normal to 0 suddenly, rule out the other stuff first.

You have not told us what you found on plumbing from turbo to CAC, CAC and plumbing from CAC to engine OR exhaust brake status.

[katlen86]

All plumbing looked fine no cracked hoses or broken clamps, exhaust brake damper moved. How do I tell when damper is open or closed, the ram that opens and close damper is all the way in, but I can get it to move its pretty tight.

[wolfe10]

You don't say what exhaust brake you have, but if a PacBrake, if rod "C" is all the way inside the cylinder, the brake is OFF:

http://www.pacbrake.com/index.php?page=maintenance-4

[katlen86]

Its a Pacbrake and the cylinder is all the way in, I turned off the exhaust brake the other day. Does this mean the damper is open or closed.

[wolfe10]

Its a Pacbrake and the cylinder is all the way in, I turned off the exhaust brake the other day. Does this mean the damper is open or closed.

When the rod is all the way in, the brake is OFF, the butterfly is OPEN, it is not restricting exhaust gas flow.

Also, check your air filter minder reading to see if you have any restriction on the air intake.

When you start the engine and rev it up, do you hear the turbo spool up as usual? Should be very obvious, particularly if you are standing near any turbo diesel engine.

After going over the basics yourself, you really need to get a diesel tech (preferably a Cateprillar diesel tech) to take a look at it.

[katlen86]

Thanks

[katlen86]

Ok one more thing were the turbo mount to the exhaust manifold there seems to be a damper there the rod goes down to an actuator it won't move up or down its stuck I think.

[dickandlois]

Reading the complete thread I did not see the air supply hose that runs from the intake manifold to the input of the air compressor mentioned.

They can fail and the loss of bust occurs.

A blown hose will produce a whooshing or similar sound.

Happens on the Cummings Engines,not sure how Cat makes the connection.

Rich.