Cam cover and breather system cleaning

[Bolin]

Hi folks, about to do this job this week.

I am going to clean out the cam covers, fit new gauzes and gaskets, but should I clean under the gaskets, around the camshafts themselves? I'm a bit worried about the cleaning stuff getting into the oilways.

And is it worth spraying cleaner through the throttle body when it's all back together, or should I clean the manifold before fitting (replacement to be fitted)?

Also, what is the best stuff to use, I have read of carb cleaner and petrol being used, but what is the most effective?

My breather pipes are both 8,500 or less, is it worth spraying cleaner through them anyway? Can't see that it'd hurt.

Advice appreciated, thanks, Bolin

[Bolin]

Well I've got some Wynn's carb cleaner from Halfords as it has good reviews.

Can anybody help with the other questions?

[SD1too]

I am going to clean out the cam covers, fit new gauzes and gaskets ..
The gaskets are sheet metal and won't need replacing, just cleaning.
Don't overlook clearing carbon deposits from the very important pinhole behind the gauze on the suction side.
... but should I clean under the gaskets, around the camshafts themselves?
No, for the reason you have given.

Simon

[lovema75]

The gaskets are sheet metal and won't need replacing, just cleaning.
Don't overlook clearing carbon deposits from the very important pinhole behind the gauze on the suction side.

No, for the reason you have given.

Simon

I hesitate to contradict Simon:bowdown::bowdown:, but when I did them on my last car they certainly were not sheet metal. I took many hours to carefully remove all traces of the previous material!

[Bolin]

Don't overlook clearing carbon deposits from the very important pinhole behind the gauze on the suction side.

No, for the reason you have given.

Thanks, I've leave underneath then and will be looking keenly to see what my pinhole is like.

I think Haynes said to fit new gaskets, and they *usually* quote MGR advice, also I had read of somebody having a leak when reusing them so I've already ordered some to be on the safe side.

lovema75 - I thought they were metal too, perhaps somebody made their own from convential gasket material and fitted them to your car before you got it? Or perhaps a cheapo brand doesn't make them from metal?

I think I'll try cleaning the manifold before fitting, to avoid stuff getting ito the engine.

[lovema75]

Very likely after-market as you say.

[robwijnstok]

It depends on how much contamination you will see and in what state it is.

Carb cleaner, petrol or brake cleaner will do, but you could find a layer of hardened caked stuff what you only can remove mechanically i.e. a flat blade screwdriver.

If you remove the two gauzes you should see a big breather hole and a small one.

If you look here http://www.the75andztclub.co.uk/forum/showthread.php?t=104108&highlight=cover you can see how mine looked. It took about an hour each to clean.

25571 A still running engine 1
25572 A still running engine 2
25573 A dead engine 1
25574 A dead engine 2

I hope you are in time, and cleaning will be an easy job to do.

Rob.

[Bolin]

Thanks Rob, I had been reading your thread with great interest.

Luckily my throttle hasn't stuck in the cold, but I do have a LOT of oil in the manifold which probably won't help the spark plugs much!!

If mine is particularly bad I'll post some pictures.

EDIT: I should mention that when I look in through the oil filler hole it looks like a coal mine inside!

[robwijnstok]

Too long oil change intervals, quality of the oil, lots of short trips etc are all factors what will not help to keep your engine clean on the inside.
Use of full synthetic oil and oil change intervals of 15.000km or 10.000miles seems to be a good way to prevent this contamination. At least with the engines that are on to this schedule units now.

Last but not least you are keeping the Winter Gremlin out of your car in the winter...

Rob.

[SD1too]

... when I look in through the oil filler hole it looks like a coal mine inside!
It will do. You're seeing the sheet metal cam cover gasket which I mentioned, and it's black (at least mine were). It's not a conventional gasket which makes contact only with the mating faces, but extends across over the camshafts. You'll see for yourself when you lift the covers off.

Simon

[Bolin]

Indeed, but it looks rough in texture, like a coal face - I bet it was smooth when it went in there!

We'll see when it comes out.

[robwijnstok]

Yep, sounds like some fun time during your screwdriver treatment while cleaning your the rocker covers...:o

[Bolin]

Now done.

I used a lot of carb cleaner, a screwdriver, a wire brush, a tootbrush and wire wool to clean the cam covers - took bloomin' forever, literally a few hours, but I got them clean! Both pin holes were blocked, now unblocked and new gauzes fitted.

Also did this for the throttle body & IAVC, and fitted a new gasket & o-ring kit to it. Also cleaned the rubber hose from airbox and I squirted carb cleaner through the breather hoses. I cleaned some small deposits from under the cam cover gasket with a small screwdriver and kitchen roll, but it wasn't bad under there.

I cleaned out the replacement inlet manifold first with a bottle brush and submerging in water with washing up liquid, which did a bit but wasn't totally sucessful, and then by squirting lots of carb cleaner through it and brushing with a bottle brush followed by flushing out with a hose.

The 'coal mine' effect was a layer of muck on top of the gasket, same as on the inside of the cover itself. My rear gasket appeared to have signs of leakage around it, so I'm glad I replaced it.

My cam covers appear to be worse than Rob's, but I'd not had the problem of a freezing throttle. Mileage 108,000 miles.

https://lh4.googleusercontent.com/-U_RbRkJoPFo/UitG6xZRnGI/AAAAAAAAAks/VyYMDDiVbAQ/s1152/IMG_8462.JPG
https://lh4.googleusercontent.com/-CsEloxI5_qo/UitG9i8auLI/AAAAAAAAAk0/QiXPduWVWeQ/s1152/IMG_8478.JPG
https://lh3.googleusercontent.com/--RK30N_NwZY/UitG_cQC04I/AAAAAAAAAk8/VcEHc6JCrL4/s800/IMG_8465.JPG

Rear cover was similar, thankfully both nowhere near as bad as the ones Rob has shown above! Now as good as new.

I will keep an eye on the pin hole and see how long it takes to block up and note the type of journeys that I make.

Thanks to Rob for highlighting this problem to the club.:bowdown:

[robwijnstok]

Glad you are sorted that out...

You have done a great job with your cleaning it looks like almost new!

Just for the record, how many miles did you drive this car from the day you bought it?
What sort of oil do you use with oil changes 5W30-40 or 10W40?
Semi synthetic or full synthetic?
What oil change interval did you use?
Any history on oil changes from previous owners regarding this questions above?
Does your car has a tow bar?

Rob.

[HN02 VDG]

Be warned the breather pipe is very brittle so go gentle with it. i find that a good tin of engine cleaner added to the oil just before a service cleans without the need to dismantle. i also ad a tub of oil seal replenisher to the oil to keep the oil seals and rubber gaskets in good condition. check your plug ports for oil that gives you an idea of the condition of your top rubber gaskets

[tonybel]

Interestingly I've just changed a 2004 engine for a 2003 kv6 and the front rocker cover breather hole was not drilled, though the plumbing and gauze filter were in place. The hole is there on the 03 engine which makes me wonder if its a MGR error, or a late modification?

If so, it begs the question why?

[ZedTeeTee]

https://lh3.googleusercontent.com/--RK30N_NwZY/UitG_cQC04I/AAAAAAAAAk8/VcEHc6JCrL4/s800/IMG_8465.JPG

Where did you get the new gauze from?

[Bolin]

Glad you are sorted that out...

You have done a great job with your cleaning it looks like almost new!

Just for the record, how many miles did you drive this car from the day you bought it?
What sort of oil do you use with oil changes 5W30-40 or 10W40?
Semi synthetic or full synthetic?
What oil change interval did you use?
Any history on oil changes from previous owners regarding this questions above?
Does your car has a tow bar?

Rob.

Hi Rob - bought in Feb 2011 (but barely used until July 2011), just under 100,000, now on 108,700 (but not used since mid-June due to problems). I don't know what condition the cam covers were in when I bought it.

Mostly short local trips, ~ 5 miles each way, with occasional return trips of 100 miles each way on the motorway.

I use 10w/40 semi, changed every year - I will start changing every 6 months from now.
Service history suggests oil changes once a year, also 10w/40 when mentioned in the records.

No tow bar and never had one.

Be warned the breather pipe is very brittle so go gentle with it. i find that a good tin of engine cleaner added to the oil just before a service cleans without the need to dismantle. i also ad a tub of oil seal replenisher to the oil to keep the oil seals and rubber gaskets in good condition. check your plug ports for oil that gives you an idea of the condition of your top rubber gaskets

Both my pipes at the top of the engine have been replaced since I bought the car, the other pipes were OK but yes I was gentle.

I have heard mixed things about using oil flushes on these engines - some people say it can dislodge muck and block oilways. Not sure whether to use it or not now that the cam covers are clean, not sure if there might be other desposits in the engine elsewhere.

The desposits I cleaned by hand I'm sure wouldn't have been changed much but a usual oil flush product.

Plug ports were dry, on mine the gasket is steel as per OE. I'll look at seal replenishers, not heard of them before.

Interestingly I've just changed a 2004 engine for a 2003 kv6 and the front rocker cover breather hole was not drilled, though the plumbing and gauze filter were in place. The hole is there on the 03 engine which makes me wonder if its a MGR error, or a late modification?

If so, it begs the question why?

Sounds like an error! Otherwise why have the pipe there and why not instead block off the other end of the pipe, saving the cost of a pipe?

Are you sure that there is no hole, and that they are not just totally blocked and clogged such you can't see them? It'd be a huge error to make:(

Where did you get the new gauze from?

Rimmers, probably also available from Endon or local Xpart stockist.

[ZedTeeTee]

Got a part number for them me old sprocket?

[Bolin]

LDM100080

£3.18 each + P&P, 4 needed. A bit pricey for what is is perhaps, but I didn't want to re-use the old ones in case I couldn't get them fully clean or they disintegrated.

[tonybel]

Sounds like an error! Otherwise why have the pipe there and why not instead block off the other end of the pipe, saving the cost of a pipe?

Are you sure that there is no hole, and that they are not just totally blocked and clogged such you can't see them? It'd be a huge error to make:(


I'm sure, small hole was there (but clogged) large 12mm hole was missing. Back head was drilled though, September 04 engine; not all heads always have there own breather so I was wondering if it was a design change to perhaps reduce crud to the VIS?

[ZedTeeTee]

LDM100080

£3.18 each + P&P, 4 needed. A bit pricey for what is is perhaps, but I didn't want to re-use the old ones in case I couldn't get them fully clean or they disintegrated.

Many thanks Colin, saved me searching....:}

[Bolin]

I'm sure, small hole was there (but clogged) large 12mm hole was missing. Back head was drilled though, September 04 engine; not all heads always have there own breather so I was wondering if it was a design change to perhaps reduce crud to the VIS?

Ah the bigger hole not present - hard to miss that.

Well the rear large hole is joined to the front by the pipe, so in theory you'd get half the crud, but surely they'd have deleted half the pipe too?

I've never heard of this before, really does sound like an error - as if it skipped a stage in the manufacturing process.

[robwijnstok]

I have heard mixed things about using oil flushes on these engines - some people say it can dislodge muck and block oilways.

The desposits I cleaned by hand I'm sure wouldn't have been changed much but a usual oil flush product.

Hi Colin,

:smilie_re:You are right regarding being careful with flushing the engine in your situation.

When I did mine there was a technical man from Forte, and he strongly adviced that before flushing the oil pan was removed what we did. When the oil pan is removed you can see the other bigger gauze filter what is installed just before the oil pump. If this one is clean (mine was) the flush was ok to do. If that gauze is not clean he recomended NOT to do the flush. Chance that that too much muck will come lose and block the small oil channels and fair chance you will write off your engine that way. So better to check that before flushing, better be safe than sorry. If the lower gauze is clean I would do the flush.

I also change the oil twice a year now and my cam cover was checked a couple of months ago and it was still clean. Every second oil change I do a flush.

You can check the contamination easy if you scrape firm with your finger nail on the inside of the rocker cover through the oil filler hole. Looking through the oil filler hole just on the left side you can see one of the gauzes what gives you an indication of the contamination there, so also easy to check.

Thanks for the update on my questions regarding oil use etc.

Rob.

[Bolin]

Well after about 350 miles (220 on the motorway) there is the usual amount of oil in the throttle body, when the air filer rubbe rhose is removed, and quite a bit of oil dripped in the hose itself too, about the usual amount I'd say.

So cleaning them hasn't made any difference to the amount of oil getting through as I had thought it would (I was wrong! Why had I thought that?), I guess this is how the system is meant to work, and with the gauzes clean and pinholes unblocked more oil shoud be able to get through in theory? Keeping the cam covers cleaner for the moment?

But I shouldn't suffer from a stuck throttle, that is the important thing.:)

[Arctic]

Hi Colin
Nice job i think i will be undertaking this job in the near future, as i have just noticed a bit of build up of the dark carbon/thick oil deposit inside the filler great write up :bowdown:

[SD1too]

I guess this is how the system is meant to work, and with the gauzes clean and pinholes unblocked more oil shoud be able to get through in theory?
Colin,

The way the system is meant to work, as I understand it, is that the hot oil vapour is drawn through the gauze filter by the engine vacuum. The oil is supposed to condense on the gauze and remain in the cam cover, with the gases continuing through the breather hoses to be burnt in the engine. Clearly the oil isn't being trapped, and my theory at the moment is that this is because the gauzes are too hot to allow condensation to take place, owing to their location.

The V8 engine in my SD1 has exactly the same system, except that the gauze filter is positioned outside the rocker cover. I don't get any liquid oil in the intake system of this engine, but both the cover and gauze container are much more exposed to cooling airflow than they are in the KV6. This is the only explanation I can think of. On my Rover 75 I have an experimental in-line paper fuel filter in my small diameter breather hose in an exposed position and it effectively separates the oil from the gases.

No engine designer would deliberately introduce engine oil into the inlet manifold where it could contaminate the sparking plugs, cause misfiring and affect the catalytic converter, so I see no evidence that the system is "supposed to be like that". :)

Simon

[Bolin]

Thanks Simon. My Austin Allegro has a huge great gauze mounted off the bell-housing, and no problems of oil getting through. Perhaps something like that could be added, but there is little space under the bonnet of the V6 and I don't know what temperature difference there would be i.e. if an externally mounted gauze would be cool enough - is there enough airflow under the V6 bonnet for such a thing to get cool enough? Something to think about.

Please let us know how your in-line filter goes over time, would be good to know:)