Topic

I would like to share with you all the details of a problem that occurred on an Epsom Club members MGF during our recent Autumn Leaves run.
His car is a 1997 MGF, which has covered 96,000 miles, is in regular daily use and has been serviced by a local MG Rover dealership (Acquired by MoTest upon the demise of MGR, but retained the technicians and records). The head gasket was replaced at 50,000 miles as a preventative measure.
After driving 50 miles to the start of the run, the low oil pressure light started to “flicker”, the oil level was immediately checked and found to be ok. The light stayed off when the car was restarted and only flickered intermittently during the 35 mile run. On arrival at the Pub finish, the light was again only flickering, but the engine was now making weird wheezing noises deep down inside, reminiscent of a starved oil pump and a clattering from the top, just like noisy tappets ( cam followers starved of oil??)
The F was trailered home and then taken to the local garage. They tried for many days to replicate the problem without success, checked the oil pressure and the switch and both were found to be correct, they decided to drain the hot oil after a test run and it barely dribbled out! So, sump off and the full extent of the problem was discovered.
There was a considerable amount of thick black sludge in the bottom of the sump, which almost completely blocking the drain hole, but was also blocking the oil pick up and strainer. This tar like sludge was so thick when cold that it would not pour out of an inverted cup.
Everything was thoroughly cleaned and refitted, the oil system flushed, a new MGR filter fitted and the engine refilled with semi-synthetic oil. All appears to be ok, I have asked the owner to join the T Bar and to keep us informed of progress with his 13 year old MGF.
I read about a similar problem many years ago on Ford Fleet cars when many engines were prematurely becoming gummed up with a soft black gooey deposit which Ford decided was the “combustion fall out” from a combination of unleaded fuel , semi-synthetic oils and high mileages.
Although modern synthetic and semi-synthetic oils contain detergents, I personally think that there is great merit in using a “flushing” additive at every oil change and to only use the correct branded oil, such as Castrol, Mobil, Esso etc and not a cheapo!

I don't like to cast aspersions but I had a similar experience with my Nissan.

When I bought it, it had been regularly serviced by a main Nissan dealer. All fine, thinks I. Started to get a flickering oil light, and when I took it to my own mechanic(an ex Nissan mechanic) he found the internals in a similar state, black semi solid oil sludge every where.

In his opinion, the oil had never been changed properly, just topped up and a new filter stuck on. He was disgusted! He spent a lot of time cleaning out as much as he could, and we ran flushing oil etc.

The engine still self destructed within 5,000 miles.

I have asked Kevin to keep me informed of progress with the MGF after its clean, he assures me that it has been properley serviced in the past and he has owned it for the last 10 years of its life.

i caught out a Renault dealership doing exactly the same thing on a company Renault 25 that i had, they werent doing anything but charging the leasing company for a full service, oil filters plugs etc. they made the mistake of bringing my car back too soon after a big service. wheras most company car drivers never lift the bonnet, i always looked to see what had been done.

is that the one you were on about at the run david?

never herd of this problem before, made an interesting read, fingers crossed all is ok now

adam

That's the one, Adam.
The first replacement 'reconditioned' engine dropped its big ends after 6 (six) miles!

Sadly this is a very common fault these days, even more so with so called longlife oils. Its something to do with the chemistry of the synthetic oil and the reaction with the alloy of the engine which produces large amounts of sludge. A friend of mine who runs an independant Audi /VW garage finds this in 90% of vehicles presented for service.
Chris

I'm not sure if this is a good or a bad thing, but when russell rebuilt mine last month he said the oil was like new. and I still get a top end tap, runs ok though

Not a good thing to happen, probably worth removing the sump on an older engine every so often to check the internal condition

I always like to flush. Just seems the decent thing to do.

Cheap flushing oil. Drain old oil, refil run around for a while, drain and change oil filter and put good oil in.

Every time I change Meg's oil I start by emptying the old crap out - then filling with Asda cheapo oil and Wynn's engine flush. Then drain that and change filter and new Magnatec. That seems to keep everything clean and sludge free.