Noticed blue smoke on start-up/take off, found that the air filter housing was covered in oil so removed, soaked and flushed oil separator and hose with parafin. loads of crap in it and this solved the smoking problem. The following week did lots of jobs for MOT,it passed, treated it to an oil change, a week later I have the same scenario, but now its worse. Removed top of air filter while engine is running to check fumage, seems fine even when I rev it.
I suspect it could either be:
The new oil is thinner so its working its way past the seals although I have changed the oil evey year with Halfords 15W-40 and never had this problem before.
Oil seals are wearing out, after all its 16 years old and 125k. But if this were the case I would not have solved the original smoking problem by cleaning out the separator.
I am hoping its not piston rings as that would really annoy me considering the work I put in getting the thing to pass its MOT. I intend to do a compression test , can anyone tell me the acceptable range of PSI that would indicate the engine isn\'t knackered, I\'ve not done one of these tests before. Thanks Darren
|
If it was piston rings it would burn all the time. as oil control rings arent doing their job. may only be valve stem seals leaking. ie badly cracked. is also poss the valve guides are worn. Didnt MK2 suffer and had to be modified oil supply tube to cam.??
--
Was mech1
|
|
|
Hi Darren,
Rather than looking for accurate cylinder compression values, look for differences between cylinders, and the difference between wet (a spoonfull or so of oil in the cylinder) and dry results.
Obviously, if you find a significant difference between wet & dry results, you have bore wear / piston ring problems.
If you find a significant difference between cylinders, then a wet / dry test on the affected cylinder will help determine the cause.
When you say that you have the same scenario, do you mean that you get blue smoke or that the air filter is oiled up?
If it is the smoke, then I agree with Steve, and would suggest the valve stem oils seals as the likeley culprits. If, however, it is oiling up the air filter, then the fault is more likely to be pistons/rings/bores.
I hope it turns out not to be serious!
number_cruncher
|
|
|
Strangely enough. compresion test though good example of what is wrong. Isnt definitive. I expect others to disagree.to answer if less than 150 problems. if around 160/180 psi or above not a prob. it is as far as I am aware about correct pressure on this engine.?
--
Was mech1
|
Hi Steve,
I agree, compression tests aren't the last word in cylinder diagnosis. If I found a cylinder giving a suspicious compression reading, I would probably go on to do a cylinder leakage test to pin down the cause - particularly before stripping a complex or difficult engine.
Thankfully, engines don't come any nicer to work on than Astra 1.3s!
I also held off talking about cylinder leakage because the original post mentioned that this was his first compression test.
number_cruncher
|
|
Thanks guys for the useful replies. Did a bit more investigation, sparks plugs are clean as a whistle, doesn't smoke on startup when cold , just on take off at operating temp. Suspect it is the seals which I'll replace at some point, will do a compression test just for curiosity. I agree with what you say number cruncher about the vauxhall engines being easy to work on, i wouldn't have a clue with modern cars!
|
|
|
|
