Engine Repair Help - Burning Oil Blue Smoke

[angelsix]

Ok I've had this problem for a while now where my Celica (1996 ST 1.8 UK) has been using a lot of oil, blowing blue smoke and requiring frequent sparks and oil due to misfiring obviously caused by the oil burning issue clogging up the sparks.

Last year before I figured this much out I checked every sensor (lam, map, crank, o2 etc...) and all were ok. Checked timing belt that was fine. I have checked and replaced leads, coil pack, sparks, new oil, new filters, checked exhaust (cat a little clogged but not a major issue at the moment) so I am pretty confident in saying the only issue with the car is really the burning oil issue.

It failed MOT due to this so is off the road for now while I fix it.

I know the issue is likey in Cylinder 1 (or whichever it is classed as, furthest to the left when looking under the bonnet, closest to driver side) as every time I change the sparks all 4 are normal except that one which is saturated and blackened, so I think I will be looking there.

Just a bit of advice really in possible causes of burning oil and things to look for, how to best repair them and so on. I am thinking perhaps a score on one of the bores meaning I just get a short engine block replacement or rebore the block, or perhaps blown gasket... but that would cause mayo in cap and I have no symptoms of that. Finally I think it may be a poor valve stem seal as the blue smoke is only when accelerating. If that is the case can anyone provide a guide or help on how to fit a head gasket kit and do I need to drain the engine oil etc...?

I have a compression checker (goes in place of spark plug) so can do another compression test later but the last time I did this there was no loss, and also have an OBDII kit and no error codes come up - but I could use that to look at other stats if someone has an idea of what to look for to identify the issue.

Luke

[GT4 BOOSTER]

could just be the valve stem oil seals need renewed ?

does it spew out alot smoke on start up ?

[Jamesbelfast]

Try a dry and then a wet compression test or have a leak-down test done.

If youh have access to a decent compression tester carry out a compression test and note the figures. Then add about a thimble full of clean engine oil to each cylinder and repeat the test. Then compare the figures. If it shows improvemnt then the problem is likely to be worn or stuck piston rings or bores.

A leak-down test is carried out by special piece of kit which supplies a regulated supply of compressed air which is piped in via the spark plug holes with the appropraite cylinder at the top of its compression stroke. The kit has a gauge which measures for long each cylinder can retain a given pressure.

[angelsix]

It doesn't seem to smoke must on startup no, but is mainly on acceleration and deceleration so that is what's making me think valve stem seals.

Save testing even more I am going to start by fitting a head gasket kit including the stem seals as it is only £80 so I'm going to give that a go first - worst that happens I have fresh new seals!

So, can anyone give me any guidance on required tools and help on fitting all the seals and gaskets etc...

Luke