3.0 TDI - What is normal Turbo Boost

[Tony]

Hi guys, me again! Ok now i've had all that work done on my engine, with all the ceramic coating & teflon & 3" downpipe etc etc... My Troll was riding superbly all the way down to the Cape, and apart from the temp. sensor giving me all that flack I had no problems whatsoever.
On my return trip, however, I noticed a slight lack of oomph - nothing major, but she just did'nt feel as lively as before and also my EGT's climbed a lot faster up hills. Now, watching my boost readings on the Madman, they seem to be a lot higher than before - I am seeing 1.4 bar spikes all the time on acceleration, and then it drops to 0.2 - 0.5 depending on accelerator pressure.

Also when cruising on a level road, and applying just enough throttle to maintain 90 - 110 km/h my boost reading settles at around the 1.0 - 1.1 bar and stays there until there is a change in throttle pressure. If I accelerate, it climbs up ti 1.4 before dropping right down, or if I lift my foot off, she drops immediately to the 0.2 - 0.3 mark or below.

I can't say that I have noticed my boost ever showing that high in the past, and when I ask Steve Green at RGM he says that the boost is fine and (in his opinion it's not too high) also with the level road cruising showing 1 bar boost - he says that the boost that is being generated all the time needs to go somewhere, and although showing on the gauge it's being dumped out the wastegate. Also, the only time that I need to be concerned about high boost issues is when there are high EGT readings at the same time.

Now I am noticing higher EGT's as well, I mean, I never recall getting close to 550 Deg unless climbing a really long and steep hill - now, I am there just driving from Malibongwe Dr on the N1 up the hill to the William Nicol offramp and that's not so long or steep.

My question is ..... what should the 3.0 TDI be reading EGT and Turbo Boost wise??

I really thought my EGT's would be much lower with all the cramic coating that I have had done - or can the engine / components simply handle more heat now with all the ceramic & teflon? Under bonnet temps. do feel a lot cooler though.

My gut feel is that the boost / power delivery is not as it was. RGM did another dyno when I returned from the Cape and the power & torque figures showed up exactly the same so it's a little hard to put a finger on the cause - any ideas anyone.

I am doing a trip to Botswana on 6th July and really do not want any other issues!!!

[Peter Connan]

Tony, as you know I am not a Diesel expert, but here are some thoughts:

Firstly, Ceramics etc do not lower EGT's, they allow the engine to handle higher EGT's.

Secondly, 550 degrees is not a lot, and shouldn't cause any problems. You do need some temperature there, particulalry if you are using power. I would not be concerned at all untill temperatures exceeded 650-700, but with all the ceramics, you should be able to comfortably handle even more than that.

What Steve says also makes sense to me.

[Tony]

Thanks for that, Pete - i've been a little concerned because we were thinking of maybe hiring a trailer to take with to Bots, but with all the sand it might not be the best idea, and where will EGT's go pulling that through soft sand.... maybe not a good idea!

[Tinus lotz]

Hey tony
I agree with Piet you made provision for hotter engine it still needs to make heat to work
I am no turbo diesel expert but Greg told me that they go up to 1.8 some times .if the engine is happy drive it I think you need to start trusting the madman and enjoy the car pulling a trailer on the sand shouldn't be a problem
To get back to the amount of boost I think it changes all the time as you have a variable vein turbo

[Kagiso II]

Yissssssssssss ingilsman !! and welcome bac .. yu been quiet 4 a while ??

Yer quest: (a) Peter Connan is 100 % correct.
(b) i have a thought on the turbo .. but let Jan at TURBO WORKX 012 653 2295.. [praat met JAN] service the turbo [not overhaul] .. and double check the shafts ballancing is OK .. and all the finns are still in shape [even a NEW turbo can pick a piece of dirt to play havoc or just bend or break something in there.
Especially if it has been recently installed or worked on or around it

[Tony]

Ag dankie Oom, you make a good point there, the turbo was replaced by SAC just over a year ago - but was stripped and coated a little while back .. I suppose it is possible that something could have got inside. Oh en ek is nie eintlik 'n ingelsman.... my bloed is 100% Italiaans, maar het meer SA Boertjie in my van hierdie lieflike land van ons!! So los maar die "ingels" uit ek is een van hulle nie orraait!! As jy moet, kan dit aaaiiitaaii wees!

[ricster]

hahahaha...... Tony...and Oom Mac has a surname - Mc Menamin - I'm still looking for the boertjie there..... eish..... me I'm toooooo much confused...

[Kagiso II]

aitog .. maak ik die verkeerde Tony die Ingilsman .. sorri man ..
Ricstr.. Oompie is Afrikaans by choice, even though the old blixzm grew up Ingilsman..