[marks152]

Ive just been to look at my sisters Z10XE corsa. The complain was a scratchy sound when accelerating and feels like its going to stall so ive just been to look at it.

First thing was a code check - no codes on pedal test - didnt have laptop with me

Checked oil - just below minimum so ive added another litre

Started the car and its probably best described a a clackety sound when you rev it. Now the chain been rattling for years and although you can hear the chain rattling this is a slightly different noise to the normal rattle from it. There is no rattle when driving at constant speed or idle -other than normal rattly camchain. The noise only comes when you either rev it to drive off or rev it when stationary. The noise only lasts a second or 2 and its gone. It sounds like its coming from the back of the motor more towards the chain.

Ive had a feel of the motor and it appears to have maybe a slight missfire although it is a 3 cylinder so I might be going down the wrong path with this. exhaust note also doesnt feel 100% smooth when you hold your hand in front of the tailpipe - could someone confirm if it should feel smooth. My feeling is it should.

Ive pulled the plugs out and they all looked pretty black and old - the car never gets warm and does 2 mile each way to work.

After a quick drive its apparent that its reluctant to pull away which may back up my ideal of a slight missfire, its abnormally slow. Its more airbox noise they go lol - Maybe timing issue

Ive ran a compression test on it on a cold engine with WOT and results were:-

Cylinder 1 = 160
Cylinder 2 = 175
Cylinder 3 = 185

So compression is a bit low but it was a cold engine. (spec is 203psi min)

Ive performed a basic coilpack test using a test lamp and all 3 were capable of jumping the spark 15mm+ but the battery started to go flat so didnt try any further.

So this is where I am at with it now. Ive asked her to drop the car off tomorrow where ill have a few hours on it tomorrow with my tools and hopefully come up with some answers.

I think ill also throw a vac gauge on the inlet and check for a clogged cat/timing

I think ill repeat the compression test on the engine with it hot @WOT. If compression is still low I think im going pull the camcover off and check the timing hasnt jumped a tooth.

If timing looks good then im gonna pull the scope out and see whats happening with primary ignition just to rule out the missfire. Im thinking that maybe the noise when you first accelerate could be a missfire which is causing the chain to abruptly slap the casing creating a different noise than normal. Maybe im barking up the wrong tree with this one but a easy check.

Ill obviously be checking out the MAF as this is the original from new with 100k on it.

Ill get some live data from it tomorrow when she drops it off and see if anything jumps out at me.

Ill throw a set of plugs in it too because ive got them in stock lol

Any more suggestions gratefully received.

 

[g4vvq1983]

Hi Mark, you get around a bit....my first thought was catalytic converter honeycombe breaking up and rattling, maybe blocking of exhaust at certain times...i have same engine in my Corsa C and that chain has been rattling forever, when i bought it, it had done 19k now its done nearly 80k, if i rev it a bit noise disappears, i change the oil and keep it service regularly..it does sound a bit timing chainy, you know those engines, the rattles are usually Timing Chain, Tappets and Water Pump....i think if the primary ignition was playing up the rev counter would be erratic, i also think a good coil with NO compression the spark should jump at least 1/4 inch...under compression it only has to jump about 40 thou or 1mm is that...so irmm little challenge for you, onder if the chain tension is getting poor or low oil pressure, i know what you mean about 3 cylinder engine not being very smooth, if it was a 4 you would say it was running on 3 lol, Compressions sound ok to me, bit low but not too bad.....might be able to get some codes or live data...good luck with that..from Fred in Essex.

 

[andy-v]

could it be a stuck lifter mark.

 

[marks152]

Tell me about it Fred. Never a quiet moment lol.

Im getting a good 15mm (approx 5/8 inch old money) - minimum of jumping spark with no compression. My plan is to stretch it a bit more and hopefully maybe see one lower but the battery was on its way after compression testing an me leaving the door open so interior light was on.

Im thinking possibly cat blocked rather than broken. The cat doesnt sound rattly. Just had another thought. About 6 months ago she complained about someone shoving what she described as black fur up the backbox. This obviously wasnt the case and it was in fact the waddng from inside. Maybe this had caused a blockage. Ill get a vac gauge on the inlet an see if if im getting back pressure which will confirm If it indeed a exhaust restriction. I can then look into it further if the test shows a restriction.

Im pretty sure the noise is the chain and not a lifter. Its too erratic to be a lifter. This noise only happens when you touch the accelerator for a split second. Sounds like something flying about inside the engine and hitting hence me thinking its a chain noise. Oil pressure was checked about 12 months ago and was perfect but its a 2 minute check so ill check it again.

The waterpump sounds to be in good order. Ive had a listen with my big long thin screwdriver and the pump actually sounds pretty quiet for one thats covered 100k.

I think ive got a few avenues of exploration but I think my first is going to be vac gauge on the inlet paying attention to what vac its pulling at idle, snapshot and its reaction when held at 3k. I think the exhaust restriction is the easies and fastest thing to rule out using the gauge.

 

[g4vvq1983]

Yes ok Mark, i have heard an engine do that when its Pinking, i know in this day and age you have knock sensors but just a thought, she hasn't put the wrong fuel in it i suppose...i have seen Mr Scanner Danner take out the Lambda sensor at front and put a pressure gauge in there and proved the exhaust was blocked,,,,i think a vacuum gauge on the inlet should show about 17 hg at idle and drop right down at hight throttle opening if its normal..not sure if you agree with that..but think that's right,,,,ok off out to the chip shop now on my Friday afternoon Jaunt....cul Guys from Fred in Essex.

 

[marks152]

pinking had crossed my mind and symptoms could suggest pinking. Once I get the car to to me tomorrow I can hook opcom up and have a look at the knock sensor readings. Good call on the fuel. Ill take a sample from the fuel rail and have a look see if anything looks or smells funny. Ill ask her has she filled the car up recently.

Yes ive seen scannerdannners test for clogged cat but from experience these lambda's are often seized in but if you connect a vac gauge into the inlet manifold and hold the RPM steady. A blocked exhaust will also show as a steady drop in vacuum when RPM is held at 3k. If the gauge stays pretty still when held at 3k then you can confirm no exhaust restriction. Obviously if there is a reduction in vac ill start by taking the backbox off given that the waddings been coming out it seems the logical place to start.

I must admit - I do like jobs like that where there are no clue(codes) and your working blind.

 

[g4vvq1983]

Hi Mark, yes ok, we have a new President of US, yes Vacuum gauge idea sounds good, and it could very well be the exhaust, those old silencers do break up inside i suppose,...have you tried putting you hand over the tail pipe and getting someone to rev it, see if you have any pressure there, that's a good old basic test..ok good luck from Fred.

 

[marks152]

I did put my hand over the tailpipe. This was one of the first things I did but I was by myself so it was at idle only. That is when I noticed it didnt feel too smooth like a slight missfire but I didnt have another 3 cylinder to compare it to. Ive only ever done it on 2 or 4 cylinder cars/bikes.

The cars outside and ive got a mate coming to give me a hand. Hes a "belt it with a hammer" type of guy so wants to see some of the techniques I use so it should be a bit of a giggle and hopefully a second pair of hands to help be get to the bottom of it. Its not too warm out at the minute. 1 degrees at the minute but looks like its going to be sunny so should soon warm up.

Ive not been following the Trump fiasco lol. I dont know enough about it to be interested if im honest. Im sure whatever he does will never be right.

 

[g4vvq1983]

Morning Mark, it's absolutely freezing here, just been to Tescos, roads slippery and just bl**dy cold, well i'm sure you will get to the bottom of it, i must say the 3 cylinder engine isn't the smoothest in the world, prob a job to balance...yes i've met a few Hammer Men in the past, they have their place lol...good luck from Fred.

 

[marks152]

Started it up again this morning and it sounded worse than yesterday. Pretty sure it was timing related I connected my vac gauge into the brake servo pipe and instantly saw low steady vacuum. So at this point my diagnosis was exhaust camshaft jumped a couple of teeth out of time. I pulled the valve cover it was exactly that. The slot in the camshaft should have been horizontal. The chain was that slack I could lift the chain and turn the camshaft with a spanner. No need for any fancy software/scope here etc. Just my basic home made vacuum gauge and 30 minutes diagnostic time to confirm this problem. Once the cover was off it revealed both camshafts are also knackered so im waiting for the go ahead to repair or not. Ill obviously provide labour FOC but its the price of parts compared to the value of the car. Its down to her now.

 

[marks152]

My homemade Vac Gauge with custom front - courtesy of my mate - fully calibrated too LOL

 

[marks152]

Im still waiting on her decision. Ive managed to source some good guaranteed cams for about £60(not bought yet). So Im waiting to see what she wants to do. I think if she decides to scrap it ill repair it myself and use it.

Priced up the parts:

Full cheap chain kit(inc sprockets/gaskets etc) £50 + sump gasket £10
Genuine Chain kit with sprockets £85 + £35 gaskets
Oil and filter £20
Camshafts £60

So thats going to be £200 for the genuine chain kit fitted or £140 using aftermarket FEBI kit. Im steering towards genuine but if she decides to repair its she will certainly want the cheapest but if I decide to repair ill go genuine.

Ill obviously be doing the coolant too and crankseal but got them already sat on my shelf so no cost involved there.

Can anyone think of anything else I might need. I think ive covered it all. Ill obviously check the cam followers once the cams are out but they looks fine from what I could see.

 

[juanpen]

You have not said it, but I imagine you have camshaft/timing aligning tools kit...

 

[marks152]

Ive not got one but they are cheap enough. got one in my watch list on ebay for £13

 

[marks152]

Well the car is officially mine now. shes opting to scrap it so shes given it to me to scrap or fix FOC. So ive ordered a set of guaranteed cams from a late twinport corsa D with Very low mileage on for £50 delivered. Im just about to order the timing chain kit and the timing kit.

Ill hopefully have it running this weekend if Im well enough. Not been too good the last few weeks - suffering major chest infection so it all depends how I feel. Im in no rush to be honest but I dont want it sat in bit as its taking up the driveway ATM lol.

 

[andy-v]

good luck with it mark, need to get ya self better, still cold out.

 

[marks152]

Done a little bit more on it today. Ive got camshafts, timing chain set, Timing tools, Waterpump gasket and Sump gasket on order

Ive managed to get the downpipe off the cat without too much issue. 2 nuts came off not worries the other was going to snap so I used a nut splitter and a hammer and chisel and got the nut off that way. Ive cleaned the 3 studs up with a die to ensure no issues when refitting, Ive removed all the alternator, airbox, engine mount, waterpump, Aux belt and tensioner. Ive also took most of the bolts out the sump and timing casing but left them attached until the parts arrive. The last thing I want to do is leave the engine open to the elements. I also found that the AUX belt tensioner was seized solid on the pivot point so ive stripped this down and sorted that out. Im about 1.5 hours in the job but ive took my time. Im going to drop the sump completely and clean the strainer because I know the cars had a hard life with only 1 oil change in 50k so im expecting to find all kinds of sludge in the sump and on the pickup gauze although oil pressure was perfect about 3 months ago when I checked it but its worth doing while its all in bits.

This is where its upto now - This engine is a piece of p*ss to work on.



I also need to remember when fitting the new sprockets to fit the old spacer from the sprocket or its going to end up with P0340 - seen this loads of times.

Im going to remove the coolant tank tomorrow and throw it in the dish washer to remove all the staining from inside the tank. I also plan on removing the throttle body and cleaning this as it looks pretty dirty.

 

[andy-v]

ya ever done one before mark, or is this ya first.

 

[marks152]

ya ever done one before mark, or is this ya first.

Ive never done one on a corsa but ive done loads of timing chains on motorbikes and cambelts on cars. I also recall doing a Saab 2.3 B234 chain kit on my dads saab 9000 - now that was cramped for space lol

 

[andy-v]

never done one me self yet.