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Zetec Strip Down


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Guest subaru

Hi everyone.

The cause of the rough running hood was due to low compression on the rear two cylinders. Looks like not even a Zetec is Chris proof. I am going to take the Cams and Head off and wondering if anybody has taken one apart before. Do the cams have to come off seperately from the head and does any one have some tips.

Thanks Again Chris.

 

ps My aim is to have this repaired before Stafford show.

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If it is a standard engine my advice is chuck it and buy another from the scrappy. Easily the cheapest route. If it's an engine with headwork, porting, upgraded cams then pull the head and consider a new short engine or a complete scrappy engine for a short block.

 

Have you done the compression test with throttle open. Repeated with oil down the bores. Have you tried a leakdown test. All are easy to do and will help you diagnose the problem before you strip the engine. If you know the fault you can decide on the best course of action. If it's rings or bore wear then it makes no sense to continue with this engine. Even with valve damage the work involved plus the costs of a head set, valves, possible skim and new head bolts makes it questionable to strip and repair.

 

If you insist on stripping it you can remove the cam cover, cam belt and then the cam carriers to get the cams out. Then manifolds, pipes and headbolts leaves you holding the head and wondering what to do next.

 

Nigel

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Totally agree with Nigel. As we discussed Chris if you want to strip as a learning exercise and for curiosity purposes go for it but don't spend money rebuilding your standard engine. There have been one or two for sale on here recently for sensible money, if not go to a scrappy and pay £200-£300 for a 2ltr blacktop (bit more for a really good one maybe). Mine originally came from a scrappy - 8000 mile engine from rear ended car cost £350. Beware ebay ripoffs being sold for £5-600 + with 100k+ on the clock. Don't be afraid of one with a few miles on though as you won't be doing many comparatively to most everyday cars.

 

Still surprised you've managed to break a zetec. Impressive. Maybe the low oil level had an effect after all. Also I've checked the program you had in the ECU and it had been messed with as you suspected over Richard's original, both fuelling and ignition. Dangerous game on what was a well setup engine. I have the original program for that car to give back to you when you're ready, although by experience with a new lump you may need another rolling road session. The modified program could have been causing pinking / underfuelling etc and may be the root cause, especially as you say if its not been performing well for a while. Would be interesting to know what's mechanically gone wrong anyway.

 

Best of luck

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Guest subaru

Hi Gents,

Thanks for the input. I think by strip down i meant take head off. Do i need to do this to have a look at the state of the valves, pistons etc or as i think you are both saying just bin the engine and get another one.

cheers chris

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As a minimum do a compression test dry and then repeat with a teaspoon of engine oil down the spark plug hole. If the compression comes up then its worn bores or knackered rings and the engine is definitely for the bin. I would then swap it anyway but afterwards out of interest I would pull it apart to look at the head gasket and the valves. (And save things like the head complete if it was good, oil pressure switch, crank pulley, thermostat housing, coils, leads, water pump, oil pump, etc for the come in handy box) Yes I do have quite a big come in handy box full of stuff that will never come in handy!

 

Nigel

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Guest subaru

Hi Nigel,

Thanks that sounds like a good plan, i wasn't aware of the teaspoon spoon of oil trick to confirm bore or piston ring wear. Hopefully alot of the bits will go on to the new engine but as you say, you never know when the come in handy box will come in handy, even if it never will!

cheers chris

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Guest subaru

As a minimum do a compression test dry and then repeat with a teaspoon of engine oil down the spark plug hole. If the compression comes up then its worn bores or knackered rings and the engine is definitely for the bin. I would then swap it anyway but afterwards out of interest I would pull it apart to look at the head gasket and the valves. (And save things like the head complete if it was good, oil pressure switch, crank pulley, thermostat housing, coils, leads, water pump, oil pump, etc for the come in handy box) Yes I do have quite a big come in handy box full of stuff that will never come in handy!

 

Nigel

 

Hi Nigel,

I have done a compression test with a teaspoon of oil and the readings were the same under 7 and under 8 bar on cylinder 4 and 3. This could from what you are saying suggest bores and rings ok possibly leaving Head gasket. Would i be right in thinking that you would advice an Engine change any way rather than trying to take the head off.

cheers chris

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well thinking logically there are only 3 ways you will be losing compression. Down the bores, a break in the head gasket or burnt valves.

 

By putting oil down the bores you've eliminated that cause. so it should be either the head gasket or the valves.

 

If it was my engine i'd take the head off, if the valves are worn you will see and i wouldn't bother getting it recon'd. I'd maybe replace the head if the bores looked good and i could get a good cheap one.

 

If the head gasket is gone you should see the marks on the head or the gasket of the blow by. If the head is heavily pitted its probably game over for the head but you could get it skimmed if its not too bad. Ive had this done by a local engineer and it wasn't that expensive. Head gaskets are pretty cheap i did my punto teh other day cost £13 for the gasket and i bought new bolts which were about £10. So it was back running for £25.

 

you need to check the head isn't cracked or warped if you do want to re-use it.

 

Either way i'd say it is worth you taking it off to see what went wrong and hopefully learn what to look out for in teh future.

 

good luck

hth

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Guest subaru

Hi Agent Zed,

Thanks for the advice. My hunch is its Head gasket rather than valves but i shall have a look before i decide weather to replace the Engine. So if its valves then new head or Engine but HG can be replaced aslong as the head isn't pitted or cracked. I have my Haynes Manual for Focuses with Zetecs on order. Fingers crossed.

Thanks chris

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