10 replies to this topic

[paul6266]

Model: City E
Year: 1987
Description of problem (please be as in depth as possible):
when the car is running I can see oil around the base of the dipstick and when you remove the dipstick it splashes out?

I belive this is excessive pressure in the sump possibly caused by worn piston rings??? what im after is can somebody else confirm this or even maybe help shed some light on this....maybe even a simple fix for it....

[samsfern]

sounds like its breathing heavily, this is normally caused by piston blow-by, so worn rings, but id have thought youd be able to get an idea by doing a compression test, do a compression test the normal way first, then do another compression test, but squirt a bit of oil down the bores, if the readings on the second "oiled bores" test are higher, then this would definately suggest piston rings/worn bores.

[paul6266]

dam to be honest thats what I thought it may have been...oh well good excuse for a new motor...anyone know of any good 998 units?

[stevelane]

sounds like its breathing heavily, this is normally caused by piston blow-by, so worn rings, but id have thought youd be able to get an idea by doing a compression test, do a compression test the normal way first, then do another compression test, but squirt a bit of oil down the bores, if the readings on the second "oiled bores" test are higher, then this would definately suggest piston rings/worn bores.

I may have the same problem myself - How much difference in the compression would you expect before its a problem? just any difference or a significant amount?

[liirge]

Ensure that your engine breathers are not blocked before taking the thing apart

[dklawson]

As liirge said, check the simple stuff first before tearing things apart.

In addition to checking the breathers, perform a compression test. What you are looking for is uniformity from cylinder to cylinder, not necessarily a specific number/value. Higher and uniform compression numbers typically indicate a healthy engine but again... there is no exact pressure figure to look for. The value is influenced not only by wear but by the compression ratio the engine was built to when new.

If in doubt after the compression test, perform a leak-down test. That will help you clearly identify if you are having leakage issues and where they are (into the crankcase, into the exhaust, into the water jacket....)

[Ethel]

Even the healthiest engines have blow by and the pressure in the sump would build up to match that in the cylinders if there was no ventilation. The dipstick on A+ engines sits directly in the block whereas the original A had a tube to submerge the end in the oil, meaning it would need a bigger difference in pressure to lift the oil up the tube, like a barometer.

[jonny d]

get yourself a dipstick with 2 Orings in it that will stop the oil coming out the dipstick base and I wouldnt worry about the oil splashing out the hole with the stick removed they all seem to do that on the A+ engines as been said already the A+ had the tube omitted at the factory

[Cooperman]

Agreed. Since they removed the dip-stick guide tube, if you run the engine with then dip-stick out it will splash oil out of the hole. Even a new engine will do this.

[valve bounce]

i got a spring that is fixed to the filter to block pipe and then hooks onto the dipstick to hold it down tight, therefore no leaks but my new engine doesn't seam to have any sump pressure

[Boycie]

Does sound like it's breathing a little.. does it 'fume' when you (carefully) remove the oil filler cap with the engine idling.
The good thing about the A-Series engine is, it will most probably carry on like this for ages if, you do indeed have a little too much crankcase pressurisation.

One point to note, I've never seen an engine compression reading not improve after a teaspoon of oil so don't automatically assume you have worn bores or piston rings if the compression test looks healthier with the addition of oil.