The engine in question is a 95 Vitara G16B 1.6lt 16 valve MPI.
I have owned the engine for 10yrs and got it with 40000km on it and it has not missed a beat ever. Recently the engine had 130000km on it and was starting to use a little oil every few months so as I had it out I sent it to the mechanics for a rebuild to freshen it up.
Below is from my members thread but I am looking for suggestions on the possible cause.
After the engine went in it seemed to be blowing a little smoke, after some consecutive hard braking due to testing it billowed out enough smoke to make think the fire brigade would turn up. This smoke cleared after a few minutes and some hard revving but it has continued to use oil, when I let it idle for a while it will blow smoke and I get a black dry substance deposited on the ground from the exhaust. We decided leave it until I had some kilometres on it but it has not improved therefore I have got the front end off and am about to remove the motor to see what has happened. So far in the removal I have noticed the exhaust manifold gasket is quite wet with oil, the plugs are all black and although it seems to be running rich the fuel economy had has improved by almost a litre per hundred. The mechanic is thinking the oil rings are not doing their job but we are also going to check the head which has been reconditioned and had new valve stems and seals.
RESULTS OF STRIPPING
Turns out aftermarket valve stem seals were used, genuine are now fitted and the engine is back together and it’s been back on the road for a few days and it seems to be going better.
While it was apart we removed one of the pistons and checked the rings, there was no carbon build up around the ring (which I was told indicates the rings are sealing) the bores seem to have run in OK and there was no sign of glazing.
It’s now done around 150km since the new valve stem seals were installed and it’s used another litre of oil. Yesterday I let it idle and after 5 min once again black soot was coming out the exhaust and if I revved it black sooty smoke came out followed by blue/ white smoke. It doesn’t seem to smoke when driving and as long as I don’t leave it idling it is fine.
Since the engine was done power has increased and fuel consumption has improved, it also revs harder and keeps pulling all the way to 6500rpm (used to drop off at 5500rpm). The mechanic that rebuilt it has since closed shop and lives a fair way away which doesn’t help, I have known him a long time and he is honouring the work and has suggested letting it get more KM on it before we strip it again (although as he said last night if it used a litre in 150km then it doesn’t look good).
My concern is I don’t want to strip again and have another guess at what the problem is, I would like to try and sort it once and for all. When it was out we found a heap of oil on the pistons and oil built up at the bottom of each valve guide indicating stem seals, however when they (engine machining mob) fit the genuine seals they say they didn’t feel much tighter??
I am confused as no shortcuts were taken and we checked it all twice over before reassembling.
I think I need to find someone who is experienced in these engines and run the problem past them to get there opinion. Sometimes the simple things are overlooked and maybe we haven’t checked all the possible reasons for the problem but are assuming the worst.
Help any one
