Thread: Td5. Power loss on HOT days?!

Just a guess- IAT sensor on the manifold needs cleaning / replacing? May be gunked up.

Will watch this with interest as I have the same problem, it's as though there is no turbo fitted when it is really bad...

New silicon hoses from Allisport fitted, D2a IC, sensors cleaned a few months ago, bost controller a couple of years ago...

I'm curious about this one!

Don't know a lot about the Td5 or how it's boost compensator set-up works but I would also start by looking in this area as you have (air restriction of some kind). But if you want a different avenue, perhaps fuel pump issue of some kind? How many Kms and what is its history? Td5's obviously have a known issue in that department.

P.S. either of you see any exhaust smoke when it happens?

I doubt you've got a problem unless you are REALLY underpowered. Turbo diesels use the turbo to compress the incoming air to create more power right. Think about blowing into the coals of a campfire. The turbo is very hot. Whilst going through the turbo the air heats up. Hot air is less dense (has less oxygen per volume) and so to get the air to compress even more it goes through the intercooler. The intercooler cools down the hot air and as it cools it becomes denser so by the time it goes into the engine cylinder it has heaps of oxygen to help the fuel burn. If it's hot the intake air is hotter (therefore less dense) to start with then the turbo is hotter so heats the air up more. Then the ambient temp is high so the effect o the intercooler is not as good. In the end you get less oxygen into the engine and because there's less oxygen the ECU can detect this via sensors and will cut fueling appropriately so you don't go around blowing clouds of black smoke. This equates to a power drop. Yes it happens to my td5 as well particularly noticeable over 40degC

Sorry if you know all this and still have a problem!

I've found I get killer turbo lag with the AC on full and nailing the loud pedal in 40* temps
Other than that, it runs great, hot or cold

Lol I know all this and still have a problem...
Particularly bad when aircon is on. For example last night, ambient of about 30°, car had been off for 2.5 hours. Pulled off from the line after 1 minute of slow running, put foot down, NOTHING, revs will not build at all, had to shift into 1st gear to get revs up enough to be on boost, then 2nd gear etc, plenty of smoke seen in the rear mirror. Dangerous in that instance, very irritating generally.

Feels like there is no turbo fitted until I hit about 2500rpm then off we go. Only in the heat, much worse with air on.

I think its the nature of the beast
This can be minimized with a bigger intercooler I would doubt if it could be eliminated