mikemcc03

as title really..
fiesta ST 2005
takes a few turns to start but when it fires there is a tiny misfire car still drives fine BUT
there seems to be what looks like compression coming out of the rocker breather pipe.

any ideas what it could be??

Chip

iTrader: (3)

rings fucked probably, or a melted or damaged piston
could be head gasket too

do a compression test, and preferably a leakdown test

mikemcc03

owww great just what i need..
ok cheers for the reply

stevieturbo

How about giving some history on the lead up to the problem ?

All cars will breathe to some degree, but your description is a little vague, and only experience would be able to tell if it was ok, a little too much, or anyone could tell if it's totally fucked.

But a lead up to the problem will help diagnose better than your current description.

mikemcc03

ok i will try my best to describe.
i will list firstly that it has a supercharger an full race exhaust oil catch tank.

came out of work an started the car an it took a few more turns than normal and a bit of throttle to get it going it fired up an held at about 1.5k rev like normal but a puff of smoke came past me (couldn't see a colour as it was disappearing).

left it idle for about 10-15 sec an reversed out of spot as i pulled off again there was another puff of smoke but nothing as i drove the 500ish yard to the traffic lights waited at lights to a dual carriage way.

an when we set off i started to accelerate as i changed from 3rd to 4th (i think) about 50mph there sounded like a backfire an another puff of smoke car felt fine an drove normal so continued to end of dual when i slowed down i thought i could hear a tiny misfire through the exhaust noise picked the revs up an it rev'd free so drove home an when i stopped the tiny misfire was still there.

an smoke was coming out of the wheel arch which was coming from the oil catch tank so i disconnected the top breather hose to see what looked like smoke/compression pumping out which didnt look right to me.
so i turned it off straight away.

i found out later that day after posting in here that No:4 injector seal was knackered an leaking air so maybe it has run lean?
car still starts an runs ok i used it for work again today but kept revs below 3k
also i tried cleaning plugs today an piston No:4 has oil on it so does 2+3 but only small amounts an No:1 is dry
i hope thats enough detail an maybe you will have a better idea
cheers mike

stevieturbo

Well, you're never going to blow up an engine during normal part throttle driving. So unless there is some parts of the story missing...the engine should be fine.

If however the engine was under heavy load/boost/rpm for any periods, and it ran lean during these then yes it's quite possible damage could be done, and done very quickly.

Oil on the spark plugs is never a good sign. And if they are precious metal tipped plugs, never try and clean them with a wire brush or anything similar. You will fuck them up.

At this stage do a compression test. But things dont sound good.

1223456

had the same on my fez, was the bottom end, needed a bottom rebuild

howie1989

sounds like the rings on piston 4 are damaged as it does it under small load or valve guide or seal

Chip

iTrader: (3)

do a compression test

mikemcc03

im expecting the worse anyway an think i will go fully forged bottom end an try for 300bhp
will still compression test an check other things tho just to rule them out or if they are a problem.. thanks for the replies

mikemcc03

would any of you know if the 2.3 rods an pistons will fit.. im sure the piston size is the standard 87.5mm but will the rods bolt to my crank ok?

Chip

iTrader: (3)

If they are from a longer stroke motor the rods are probably shorter or the pistons will have the pin mounted higher up, either way it would mean the pistons sit too low.

(only way not to be is a taller block, which I dont think they have)

mikemcc03

burton power lists the 2.3 rods 154.81mm LONG
an the 2.0 as 146.30mm LONG
i thought it would be the other way round?

wouldn't the piston sitting lower make the compression ratio lower good for the supercharger?

Chip

iTrader: (3)

The crank comes up higher, so less room between it and the piston at TDC


Should think that putting the piston 8.51mm down the bore will drop the compression ratio far too much for a supercharger.

If you tell me the standard bore/stroke/compression ratio, I will tell you the new one with those rods fitted.

mikemcc03

wikipedia said the Bore is 87.5 mm (3.44 in) and stroke is 83.1 mm
The compression ratio is 10:1.
cheers for your help its much apprecited

of Pumaspeed
The pistons are also available in differring compression ratios.
2000cc engines
8.0 : 1 Turbo and supercharger
10.4 : 1 STD NASP
11.2 : 1 Fast Road NASP
12.5 : 1 Race NASP

2300cc engines
9.0 : 1 Turbo and supercharger
11.6 : 1 STD NASP
12.5 : 1 Race NASP
14.0 : 1

mikemcc03

for The Duratec 23 is a 2.3 L (140 CID; 2261 cc).[3] Bore is 3.44 inches (87.5 mm) and stroke is 3.70 inches (94 mm)
no C:R tho

Chip

iTrader: (3)

Dotn need the cr of the 2.3, just the 2.0 details and the rod length change is all I require mate.

So here it is:



bore 87.5 / stroke 83.1
Thats 499.7cc per cylinder of swept volume


Compression of 10:1 => unswept = 499.7/9 = 55.5cc

Sanity check = (499.7 + 55.5) / 55.5 = 10.003 = cool, we have the right numbers


Bore size per 1mm of height = 87.5 * 87.5 * pi / 4 = 6cc

so 8.5 * 6cc = 51

So the new unswept would be : 55.2 + 51 = 106.2 cc

New compression ratio = (499.7 + 106.2) / 106.2 = 5.7:1

So as I said in the first place, definately too low.

If it was 2mm or so, it would be fine, but not 8.5

mikemcc03

so thats that out the window.
thanks for solving that for me before i waste money on things i cant use.
looks like its 1k for internals
at least it will be strong enough to hold up to a charger..
i have just got hold of a compression tester so will be getting the readings tomorrow..
dont know where i'll get a leakdown tester from tho.. dont really want to buy one for a one time use.

Chip

iTrader: (3)

It might be so obvious from the compression test that you dont need a leakdown tester mate.

stevieturbo

Not might....It will be so obvious lol

benjaminsarmy

checkout you haven't scored a ring-land or even a piston ring mate my pgt is having the same trouble as you describe do you get pressure through the dipstick ie stick blow-out

stevieturbo

It's probably a melted/broken piston. Assuming the bores are ok or at least salvageable, it shouldnt need Ł1k internals.

Just replace the pistons and rebuild. I doubt the factory rods are so weak they cant handle it ?

dojj

iTrader: (3)

it's the same engine as a mk3 mondeo and the pistons are supposed to be the weak points on them, everything else is supposed to be fine for forced induction, but before you spend that much money on just pistons, check out the 2.3 engines as i'm sure a short block isn't THAT much more expensive than a full rebiuld for your 2.0 one

mikemcc03

so you guys think the rods will be fine?
wouldnt mine knowing the power they can handle as that will be nearly 500 quid off the bill.lol
once ive got the compression test numbers i'll post them up no doubt they will be off.
any ideas what good compression numbers i should be hoping for?

stevieturbo

rods rarely fail due to power, unless they are totally crap.

rpm's kill rods.

Chip

iTrader: (3)

+1

So many people changes rods when they don't need to.

mikemcc03

right guys i have done a compression check....
could you guys shed some knowledgeable light on the findings please?
cylinder No1-150psi peak an a leaking off fast
cylinder No2-210 seemed to hold it
cylinder No3- " " " " "
cylinder No4- 120psi an leaked of slowly.
plugs came out clean this time no oil on them at all.

stevieturbo

A few things. Either you arent doing the test correctly, or something is well and truly fucked up.
The variance on all cylinders, even for a fucked engine doesnt make sense.

And what do you mean by leaking off ? Unless your tester is also fucked, the pressure should never read off the gauge until you let the pressure out.

http://www.pumaracing.co.uk/comp.htm

Even if the readings are remotely correct.....you're engine still sounds fucked.

dojj

iTrader: (3)

did you do a dry and wet test?

mikemcc03

i just read the thing you posted an i didnt open the throttle just cranked till it peaked.

by leaking off i mean it peaked at 150psi i stopped cranking an the needle started to come back down the gauge. if there is hole in the piston or leak somewhere surely that would make the needle come down or does the needle stop an hold at its peak point?

the car still runs an drives ok with slight miss an the smoke out of the breather but ive stopped driving it not to cause anymore damage.
i will repeat the test with the info you have given me tho

dojj

iTrader: (3)

you need 2 peeps to do the test

one to crank
one to observe the gauge

remove all the plugs

disconnect the coilpack/distributor to stop the wires from sparking

crank with the throttle wide open (not sure how you do this on a car with fly by wire but i'm sure it's the same thing) and crank for about 10 seconds, or until the gauge peaks

repeat on all cylinders

then repeat with a few squirts of oil down the bores to perform the "wet" test

make sure the battery is fully charged as the last thing you want is for it to splutter and fuck all your resluts up

report back

i know it may be teaching you to suck eggs, but that's the way i've always done them

stevieturbo

Leaking off means you need to buy a new compression tester.

Do the test again with a proper tester ( Yes a Ł15 one is fine ) and conduct the test properly as per the article.

And a compression test is a one man job. It can be done faster with two, but certainly does not need two.

mikemcc03

ah right the one im using is a mac tools tester.
if it makes an difference i done as the article said an unplugged injectors an jammed throttle wide open an results are.
compression-- psi jump --- engine revs to peak
no-1- 150 90-120-150 5
no-2- 210 120-180-210 5
no-3- 210 110-180-210 5
no-4- 120 90-110-120 5

stevieturbo when you say by these results my engine must be fucked do you mean it shouldn't run? or could run but rough?

will have to get new tester an repeat
also will be borrowing a bore scope camera tomorrow so shall report findings.
thanks all

thanks dojj will try the "wet" test tomorrow in the light as i dont have to luxury of a garage

stevieturbo

There is little point in a bore scope. By fucked, it just means fucked and needs to come apart. It could well still run though, and you'll just be doing more harm by doing so.

2/3 sound pretty decent. 1/4 are nowhere near where they should be so likely those pistons have melted.

So it's a total engine strip down really.

mikemcc03

it definitely needs to come apart so while im pulling it apart i'll change the pistons but keep the standard rods as your advice from more experienced people.
so will do gasket an get all valves checked an chain changed to be safe.
thanks for all your advice guys hopefully i will have better things to report in time.

Fiesta_Jed

Just to let you know the 2.3 Duratec has an 11mm taller block, so 2.3 crank, rods and pistons do not fit in the 2L block.

stuart collins

iTrader: (7)

just put a 2.3 bottom end in it

mikemcc03

well engine is apart an there are bent valves
only very slightly an a couple aren't seating properly so they will all be re-placed/reseated where needed an all the valve clearances set..
pistons are fine an the bores have no marks or even a lip onto of cylinders an no movement in any of the pistons in the cylinders..
filled the cylinders with oil an left it an they all held the oil to..
the only thing on 3 of the pistons are slight marks where the vales must of touched.
how that happened an it still run only with a very very minor misfire i dont know..

James

Had similar on my 1800 zetec mondeo (old shape) had a very very slight missfire but otherwise ran fine. Did compression check and found number 4 was down a bit. Did a leak down test which confirmed the fault. Two cracked exhaust valves!

Amazed it ran as well as it did with such a problem, wouldnt of stripped it down but it failed mot and couldnt get a cheap estate car that weekend!

stevieturbo

You would be mental not to pull the pistons out for a proper inspection.