C14KEE

Hi guys

Went out in the turbo last nite, racing my buddies fiesta st, gave it a blasting up a mountain road up by me, car was probably flat out on boost for no more than a minute, and when i got to the top the engine was knocking and slapping inside like id popped a piston. Really bad. Ive blown a piston before in a bmw and this sounded exactly the same.
Gutted as i was, just shrugged my shoulders and began rolling it back down to the house. However, seeing as the brakes dont work unless its started, i let it tick over and freewheel down to the bottom (about a mile).

I got to the bottom and knew i had to drive it a little bit over another brow to roll home, but when i did the car suddenly started normal again! drove it easy for a bit and it was as if nothing happened?

Why did this happen?

Also, i decided to take it for the nightly spin anyway, and although it had a BIT of abuse throughout the nite, didnt play up again until right at the end, when after around 20-30 seconds on boost it started knocking and banging again, serious engine failure sounds. As i did the first time, i knocked it off for 5 and let it cool, and when i freewheeled it and put it in a high gear it started acting normal again.

Its sounding normal again now, but i dont want this happening on a regular basis. Why is this happening, what do i do to stop it and do i need to have it looked at now rather than later?

Cheers in advance cos i know theres plenty of ppl who know a thing or 2 here.

p.s. the car is the usual 180 (chip, exhaust, knN) plus a saph turbo running on around 10 psi boost. 5w50 oil.

vroooom ptssssh

possibly running on 3 cylinders? or worse sounding?

C14KEE

yea sounded like it was, but now its gone back to normal again.

How the hell can that happen!?

vroooom ptssssh

Could be a few things, check:

dizzy cap/rotor arm condition and makesure their is no water in it.
plug leads, if replacing use genuine ford.
plugs, plug gaps
hard to tell if a plug lead is fooked cos it can break down under load, but if they are old its maybe worth replacing

if all that's fine, then i'd check the injectors and do a compression test on each cylinder.

Oranoco

Could even be a hydralic lifter pegging out. Did it sound like it was top end or bottom end knocking

C14KEE

Im not an expert but id say it was the top end slapping, sounded like cylinder 2 to me......

Mad how it came and went tho. Thought i was looking at Ł500 at least damage and then she decides shes ok. Im not a worrier, this was serious knocking.

Could it be too thin oil getting too hot?

Oranoco

To me that reeks of hydralic lifters.

C14KEE

that expensive?

Oranoco

Not really but if the lifters are pooped the cam isn't usually far behind as they wear to each other. Cam kits are about Ł250 and it is a DIY job if you have some mechanical know how. If not I'd budget on 3 hours labour at your local friendly tuner.

se mk3 cabbie

yeah mate i agree, had that happen on one of mine, rattled like a pig when thrashed then after 5 minutes on idle lifters fill with oil again and were brand new

C14KEE

is it possible to change the lifters and not the cam, thats if the cam is ok to stay in???

im looking to budget here as much as possible, but if it has to be changed then it will be done!

Moonie

It is possible to change just the lifters but as mentioned previously the cam and lifters wear together so should be replaced together.

Its really down to you, personally i would change the cam at the same time.

Oranoco

Perfect time to bung a nice Kent CVH35 in eh

C14KEE

hmmmm

sounds like a good bit of cash that

Is the car ok tho to drive about normally? or am i doing more damage every time i drive it?

Oranoco

I would probably take the chance on it but I'm not a tuner. Do you really want to risk driving something you know isn't quite right?

C14KEE

no not really but i dont really have a choice as its my only form of transport.

AND its back to normal again.

What would you do?

Rick

i'd say lifters pumping up too. What oil are u using?

SafeChav

I'd also say lifters, have you checked your oil level lately aswell?

SafeChav

On the cam situation aswell, if your cam is goosed putting new lifters in will be ok for a few minutes until the cam turns them into scrap just like the old ones.

Take them out and have a look at them, IF THEY DON'T WANT TO PULL OUT EASILY AND ARE TIGHT THEY ARE KNACKERED AND FORCING THEM OUT WILL ALSO DAMAGE THE BORES THEY SIT IN. If they do come out, look at the bottom, any dishing indicates a worn cam, they should be near on perfectly flat.

On a CVH because they wear from day 1 they should only be changed as a complete cam and lifter set

C14KEE

IM using 5W50 Motorsport oil, valvolene i think

Heard the standard cam is best with a saff turbo punch anyway init? instead if sticking in a kent cam?

SafeChav

A lot of people are going back to standard cams, the kent cams raise the power band considerably but it throws you back and pulls like a slag, not much good for 0-60's though.

C14KEE

yea and the cossie turbo has already given it a poweband like a motocrosser, 3500 and hitting hard!!!!!

if i pay someone to take the head off and have a look, is he going to know straight away if the lifters are done for? as long as hes experienced?

SafeChav

Your going to like this.....you don't need to take the head off

Rocker cover off, undo the rockers, and the lifters MAY pull out but as i said if they don't want to don't force them, and that would say they are fucked.

To be honest though, if the car isn't tappy normally, and only taps for a short while after a good thrash its probably as the likes of Oranoco have suggested, your oil, or it might even just want an oil change. Whats the engine like inside when you pull the cap off? And have you checked the oil level recently?

C14KEE

well it had an oil change less that 1000 miles ago, changed the tappy 15-40 which i put in by mistake for a 5w50 and it was sounding as sweet as a nut. have not checked the level lately but seeing as it was only done recently i didnt see the need!

Safechav, i must say mate, after a good thrash, this isnt tapping, this is full blown piston knocking. Taps as loud as a car without an exhaust!! super rough!!! like a tumbledrier with a piece of lead in it!!!

perhaps the oil was too thin and ive burnt some away?

C14KEE

But yes chuffed i dont have to take the head off......now how the hell do i get a rocker cover off, theres a big pipe with a dump valve in the way!!!

SafeChav

Come on its time for the boy to become a man and learn how to get that rocker cover off, its easy mate you will see how

Hmmmmmm if the knockings that loud then maybe it isn't but bottom end noises don't usually come and go, i think the majority on here have pointed at lifters because they operate from the pressurised oil supply.

To be honest though if it is a lifter thats intermttently playing up your not going to be able to tell a lot by looking at them?

C14KEE

Yea that was what i was thinking, its intermittent.

If its only happening after a SERIOUSLY heavy booting, then maybe i should just leave it and change up to a 10w50 oil? perhaps the 5w50 is burning out too quickly....il check it now this morning see what my oil levels like.

Safechav, u still got that battery clamp??

Perhaps i need a intercooler....anyone got a GRS or NMS for sale!!!

Moonie

An intercooler isnt going to solve a lifter problem mate.

Some good information on here about heads & cams - http://www.pumaracing.co.uk/cvh.htm

SafeChav

Has your car got the oil cooler in between the block and the oil filter? And are the pipes blocked? Worth a check.....

What battery clamp is that mate?