KAD 44 rpm surging

J

Jason JCP007

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Hi All, I’m new here but hoping to get some ideas of how to resolve a problem. Can see others have had similar issue but can’t see too much in the way of the resolve:
I have twin KAD 44’s on my 2001 Targa 34, both run fine except that port engine revs drop back when reaching near 3000rpm, supercharger re engages, revs build, supercharger, disengages, revs drop and on the cycle goes, starboard engine ok, but holding back a little for the struggling port engine. If I go full throttle, after a couple of minutes, port engine gets through this and it settles so that I can throttle back to just over 3000rpm steady, but go back a little further and surging starts again.
Local VP engineer got as far as wanting to swap over ECU’s as may prove that a turbo boost pressure switch could be faulty. struggling to get them back to do this, they are overrun with work and not taking bookings, not making it to appointments when booked, all others around me getting let down. Hoping I might be able to get the job done myself with some advise. Look forward to your replies and being part of this forum.
 
The turbos them selves are not the most robust .They internally corrode on the exhaust side and loose boost from basic air tight ness on one hand , on the other the tips of the blades seem to burn off again loosing boost .
Your symptoms are the classic signs .
Post a pic on here .Or alternatively Google the 100 s of stuff on Volvo Penta 44 / 300 turbo failure .
 
Absolute classic KAD44 worn turbo symptoms. To be honest, you're VP engineer is doing you a favour by not coming back.

If the turbos are original then I'll bet £50 that they're knackered. Buy new OEM ones from a Borg Warner outlet and get an independent engineer to fit them. I'd do both sides which should cost you £2000 (both sides including labour).

Where are you based?
 
99% its the turbos, change them both. One is clearly past it's best the other won't be far behind. It is not a difficult job to change them yourself, its also a good opportunity to change the exhaust elbows and the antifreeze mix as you will need to drain it down quite a lot. How long it will take depends on access.
 
Had the same issue with mine although KAD43. My turbos were 20 years old as well. They have done well and corrode more through proximity to salt water than usage. Agree go new not refurb. They are quite heavy but a reasonable DIY job. Note orientation of gasket and prime with oil before running. I replaced my coolent and oil change at the same time to give them a good start off.
Agree change the elbows. Don’t bother with stainless ones, the Chinese ones from Keypart will do another 20 years.
Thats £3000 spent and it not even 10 o’clock yet.
 
Last edited:
Portofino said:
The turbos them selves are not the most robust .They internally corrode on the exhaust side and loose boost from basic air tight ness on one hand , on the other the tips of the blades seem to burn off again loosing boost .
Your symptoms are the classic signs .
Post a pic on here .Or alternatively Google the 100 s of stuff on Volvo Penta 44 / 300 turbo failure .
Click to expand...
Thanks for the swift reply Portofino, I will open my eyes to a potential turbo replacement, I have a good engineer that can do that. I’ll look into what I can do myself so far as an initial inspection first maybe.
 
petem said:
Absolute classic KAD44 worn turbo symptoms. To be honest, you're VP engineer is doing you a favour by not coming back.

If the turbos are original then I'll bet £50 that they're knackered. Buy new OEM ones from a Borg Warner outlet and get an independent engineer to fit them. I'd do both sides which should cost you £2000 (both sides including labour).

Where are you based?
Click to expand...
Thanks Petem, as I replied above applies here, I’m in UK, Bristol Channel.
Appreciate your feedback ??
 
kashurst said:
99% its the turbos, change them both. One is clearly past it's best the other won't be far behind. It is not a difficult job to change them yourself, its also a good opportunity to change the exhaust elbows and the antifreeze mix as you will need to drain it down quite a lot. How long it will take depends on access.
Click to expand...
Thanks Kashurst, don’t mind getting my hands dirty, shopping list getting longer quickly ?
 
DavidJ said:
Had the same issue with mine although KAD43. My turbos were 20 years old as well. They have done well and corrode more through proximity to salt water than usage. Agree go new not refurb. They are quite heavy but a reasonable DIY job. Note orientation of gasket and prime with oil before running. I replaced my coolent and oil change at the same time to give them a good start off.
Agree change the elbows. Don’t bother with stainless ones, the Chinese ones from Keypart will do another 20 years.
Thats £3000 spent and it not even 10 o’clock yet.
Click to expand...
Thanks DavidJ, more sound advice it seems, yep, was just saying, just turning the page to carry on the shopping list. I didn’t expect so much quick sound advice here, thank you all.
 
Hi,
I changed the turbos myself - 2 x KAD300. Very easy fix. I bought the turbos here:
Turboparts1796
Original Borg Waner (same as OEM VP) - new products and not refurbished. The company has great pricing and ship instantly. All on stock.
Do the elbows at the same time like said above.
 
Keep meaning to put an update here belatedly, sorry for the delay. You guys were spot on, we got the port turbo out and it was a mess, corrosion through the cylinder, big gaps around the blades, bought two turbos from Turbo Dynamics, half the cost of VP for same turbo's, did starboard too, wasn't quite as bad but on it's way to similar condition. Elbows were fine. Took her out for a spin, problem gone, seems to get to WOT faster too.
Thanks guys, for your input here, hope someone else stumbles across the thread and saves themselves a lot of time if they have a similar issue. Take care.
 
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