Menu Sign In Contact FAQ
Banner
Welcome to our forums

Ram air TIO540

Aviathor wrote:

There is a procedure to verify the operation of the wastegate and pressure controller using compressed air.

Been there, done that :-(

EGKB Biggin Hill

It would indeed be some coincidence to have the same problem on 2 different engines with different histories… But one never knows. There is a procedure to verify the operation of the wastegate and pressure controller using compressed air.

LFPT, LFPN

Timothy wrote:

The trouble is that (1) it is the same on both engines (2) one wastegate has been overhauled very recently (<50 hours) the other about 450 hours ago (3) both have been mouse milked repeatedly.

Maybe the paragraph after the one quoted by @Aviathor could give a clue as to a common cause:

If optionally equipped with an inline strainer to the wastegate, clean the inline strainer. RAM suspects that the primary cause of wastegate and controller problems is foreign matter in the oil. Foreign matter will typically be captured within the inline strainer.

According to the information which I found, the density controller shouldn’t even be the one controlling the UDP at partial power, but the differential pressure controller. Maybe that principle changes at some (high) altitude? Or it is an issue of the density controller taking over when it shouldn’t…?

IMO it’s the density controller that’s sensitive to the ram air pressure change.

FAA A&P/IA
LFPN

The trouble is that (1) it is the same on both engines (2) one wastegate has been overhauled very recently (<50 hours) the other about 450 hours ago (3) both have been mouse milked repeatedly.

EGKB Biggin Hill

Start by lubricating it with mouse milk before replacing it :-)

EGTF, LFTF

I just stumbled over an article by RAM aircraft which has a troubleshooting section that says:

Manifold pressure follows airspeed – Defective wastegate – Repair or replace wastegate

Worth considering?

LFPT, LFPN

What I now know from flying a different PA31 (albeit a 350hp Chieftain) this week, is that it does not suffer from any of the engine control issues I have described on my own aircraft :-(

EGKB Biggin Hill

With “link” I did not mean physical but as you said Michael a second order effect. This though happens not only at WOT but at all altitudes at normal cruise settings.

LSZH
40 Posts
Sign in to add your message

Back to Top