I own a turbo Saratoga with an intercooler and gami's. The engine has 100 hrs so it is broken in and I can't get the cylinder head temps below 400 during my climb out and I am operating at full power.

This has required me to run a very low power setting to keep the temp below 400, but my climb rate is terrible. I am running full rich from take off thru climb.

Does anyone have any ideas on what the problem might be?

  • 1
    $\begingroup$ How does the fuel flow compare to the book value? The book says my TSIO-520H needs 120 pph and that’s about what I see. It is possible that even though you are at full rich, you aren’t getting the fuel flow necessary to keep the engine cool. $\endgroup$
    – JScarry
    Jul 5, 2017 at 17:34

2 Answers 2


I'll provide a bit of a general answer to this so it covers for most cases. The basic question is, "my engine is running hot on climb out, what issues could lead to this"

Cooling Air: Airplane piston engines are air/oil cooled and require proper airflow over the engine to cool properly. A poorly installed cowling or obstructed/damaged air inlets can cause airflow to be incorrect. Some aircraft also have some internal baffling to direct air around the engine bay, these parts can move or get out of place and may be causing improper flow.

Fuel: As JScarry mentions, you need to ensure you have proper fuel flow (which is key to temp control). If you don't have a flow meter installed a shop should be able to check this for you.

Procedure: This sounds like a new plane to you, are you following all book procedures for climb out? Turbo planes often have different op-specs than their NA counterparts. Its not uncommon for there to be full power limitations (e.g. full power 5-min continuous limit then reduce to XX MAP).

Timing: You may have a faulty magneto or your magnetos may be improperly timed causing an advanced ignition situation that would add stress (and heat) to the engine.

Auto-Turbo Settings: I believe the Turbo Toga's had self governing turbos but not all planes do. You should make sure the pop-off mechanism is set correctly and the turbo is operating with in its proper limits.

Set-Up: This is unique to your new engine case but it may be worth bringing in another A&P that is familiar with the Toga Turbo engine and set up to make sure everything is where it should be just in case the engine shop overlooked something.

Incorrect Indication: To add to "Set-Up", it's possible that your CHT is incorrectly calibrated or installed. (this is an edit from another poster, who experienced high oil temps to finally discover that the oil temp thermocouple was in the wrong location, and read higher than actual temps)

  • $\begingroup$ More on what Dave said on fuel and procedure. If you're running a less-than-MCP climb, are you doing this just with prop, or with throttle (or throttle and prop)? Full (or MCP) throttle manifold pressure includes an extra-rich fuel flow. If you're reducing power by reducing manifold pressure, you might be decreasing the fuel flow outside the extra-rich range. (That said, I'd look at cooling air first. And probes: you could have a faulty CHT probe, or faulty CHT gauge.) $\endgroup$
    – ammPilot
    Jul 6, 2017 at 0:51

What's your gami spread?
Do you have a multiprobe engine monitor?
Do you leave the MP and RPM at maximum allowable settings (could be full forward) or do you use some sort or reduced setting (ex. 25/2500)?
Are you following POH guidance? If you are you are probably doing more harm than good. POHs are notorious for providing sub-optimal engine guidance.

I bet good baffles and a little more fuel will solve your issue (or at least help).

First, the redline on your fuel flow is not a maximim, it's a minimum. Bump the flow up a little bit. If your IA says that is illegal you need a new mechanic. It's not illegal.

Second, check the baffles. You may need to install new ones. If you have leaky baffles on a TC engine you are asking for trouble. How old are they?

John Deakin - this is the name of an engine guru. Read everything you can about engine management by this author. He writes the Pelican Pearch series and gives very good, research based guidance.

Mike Busch - also very knowledgable.

Where are you located? Dry desert or humid coastal?


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