time for a rebuild

FS5 · 09-05-2006, 07:20 PM

i got a leakdown test done today on our au i6 .according to the mechanic it was 38% on 5 pots & 40% on 1 , i dont realy know what this means .but he showed me the gauge and it was right on the line between low & moderate.he said it was due for a bottom end rebuild.he also said he did a compression test and it was 150psi (but i'm a bit sus if he did this or not)when i did a comp test a couple of weeks ago i got 180 psi although the engine was cold when i did it.

the car has been using oil ever since i fitted the ported head,and its not a little bit in the last 8000 km its used 3 litres.it is very strange the car dose not blow any oil smoke it only blows this mustard colour smoke when i get up it after taking it easy for a while.there is no oil gunk or build up on the plugs and there is no major oil leaks .the cars only done 177000 k , but do give it a hard time when i drive it.

so wat do you guys reckon ,is it time for a rebuild ?
thanks jake

xd5.8l · 09-05-2006, 07:26 PM

If the pistons aren't alapping about for a prelonged period of time and oil pressure is within specs I wouldn't worry about it. Just keep on trucking. The mustard coloured exhaust gas is a little bit of a worry though? First thing that comes to mind is head gasket.

**Stav** · 09-05-2006, 07:46 PM

Get another opinion mate.Thats my advice.Many of these guys just want to milk us like cows. Its better to be on the safe side.

xr8ute · 10-05-2006, 12:29 PM

Bugger, thats a lot of cylinder pressure and potential horspower going down the toilet. Did he say wether it was pistong rings or valves loosing the pressure?

A leakdown test will show up engine wear that a compression test wont (like you performed earlier).

If it was a taxi, you could probably put another 177,000km's on it before need a rebuild. But if you are really keen on improving your best ET and MPH anytime soon, a bottom-end rebuild should be on the cards.

blackers10 · 10-05-2006, 12:33 PM

get a bottom end rebuild that would make the devil cringe!!
balance it with forged everything then drop a huffer on it.. *grins*

jonbays · 10-05-2006, 03:31 PM

These aren't good numbers really for any sort of performance you will need a rebuild.

This was done hot though wasn't it. running temp not cold engine.

FS5 · 10-05-2006, 04:33 PM

it was done hot ,and it was leaking past the pistons.
well i bit the bullet and ordered the parts today.not going to do nothing special to it.just going to rering it and put new bearings and chain guides .this is if we don't get any little suprizes when we pull it apart.