poly n moly! Have
Join Date: Feb 2014
Location: United Kingdom
I thought I would add to this log, as others haven't, as I have had my own turbo wear out recently.
My Garrett turbo had a little play in the shaft and didn't smoke, but after a hole developed in the upper boost hose it wore out to a point of giving poor boost response within 2 weeks.
I removed it and dismantled it, to find large amounts of shaft end float. This meant the back of the exhaust turbine wheel had been rubbing on the heat shield making the whole engine hold back from accelerating. The bearings and shaft were almost fine, but the thrust collars were very worn to the point of wearing into the aluminium backplate. The hole in the intercooler hose had caused my turbo to overspin, overpeed. I was getting peed over by much slower cars and I could see black smoke in the rear view! The pressure in the exhaust manifold pumped up the crankcase which has started pushing oil out of my crank seals! I'm not bothered as I know it will stop once the turbo's blowing properly. The exhaust turbine oil piston ring seal had turned to carbon, as usual! A rebuild would cost £140 in parts and the longevity afterwards would be questionable, so I'm going for a new hard core chaaahahaharr thats warranted. This leads to the problem of VNT adjustment/setting up(on the bench!), a service many firms offer for about £100. If the VNT is set wrong, the power from the turbo can be delivered too harshly, causing a surge feeling under steady thottle, or soggy throttle response.
Being a cheap scape, I'm going to use a free laptop based alfascan to log the VNT%, after it's bedded in, to look for about 60% VNT when it's spooling. I've heard 60% is where the ECU likes to hold the VNT, but I will not adjust it if its boosting nice and evenly when being driven from all engine temperatures.
This turbo's getting a new oil feed pipe, I'm going for a custom made one (£25 including delivery, or a Venhill one from the bay £15 (it's a banjo ended brake line, but who cares).
If I get into ****e I'll log it here lol