Recent engine rebuild ( Loudish Metalic Ticking noise)

[DaNnY_LaD]

Right i had a spare few minutes tonight and ive gone out and done what you said..On start up my engine was missing as usal and its making a slight knock on the gearbox side directly were the DMF would sit so like john said maybe the sudden impact of the engine failing has damaged my flywheel..

So anyway i plug in my vagcom and cleared any codes then let her warm up to 90c water temp and brought it up 3krpm and then EML starting flashing so no change there...So i left it at between 2.5krpm and 3krpm for roughly 10-12mins constant with a few 1 minutes breaks in between....

The engine got and felt realll hot as the fans were kicking in...everything sounded quite which was odd for me....anyway i thought with it being different il clear the codes while its still running and bring it back up to 3krpm...i had no EML light ..I then desided to take it for a drive then put my brief foot down in 2nd and was being gentle with it came to 4th goin up the same hill as last night and brought it outta boost and outta revs so there was load on the engine and No spluttering or miss fire...

I then dug deeper i tested all gears and a few engine rev gears and everything seemed fine,Then desiding to bit the bullet i came it in 3rd outta boost up to 15psi without it missing felt rather quick too...(has been 2 1/2) months...

cars idles and sounds fine BUT i dont know if this is because the engine is rather red hot and is sealing the head or Pistons ect...So il try it again tommorrow from dead cold and see if it misses....?

 

[CJRamze]

To be fair I'd think sitting there for 10 minutes at 3000RPM without moving is a sure fire way to kill an engine...

 

[DaNnY_LaD]

Like I said with 1minutes breaks too...temp gauge oil and water didn't go tohot..

 

[BBoy82]

To be fair I'd think sitting there for 10 minutes at 3000RPM without moving is a sure fire way to kill an engine...

I shouldnt have thought so.
When flushing an engine when servicing you are instructed to sit at 2000rpm for 15 mins continuous...
Also cooling fans and rad sizes are specced to cope with the heat generated by sitting in traffic for hours on baking hot days.
So long as the coolant is topped up, thermostat opens, fans/switches/relays etc all work it should be fine.

 

[DaNnY_LaD]

Started the car this morning and it was still the same but took it up the road and it wasn't as bad but its still spluttering...but after a few minutes of driving it seemed fine then it was better once hot...

What we thinking lifters or rings?

 

[hardcore4]

lifters danny, what poil are you running? have you tried compression testing it when engine is warm and operating ok? sitting with a car at 3krpm for 10 minutes will not kill youre engine if anything it will make the fans work a little harder than theyre used to!

 

[DaNnY_LaD]

I've driven 50miles already and its still doing it...so I'm thinking more.bottom end...

 

[grahams81]

Results are;

Cyl 1 : 75psi
cyl 2: 75psi
cyl 3: 75 psi
cyl 4 : 50psi.

.

Dan these results are way off - new 1.8t should be reading 170-175psi, if your only getting these results then there's a hell of a lot of air escaping either past the piston rings or through a open valve / valves.

If it were the odd lifter sticking it seems unlikely that the compression test would be wroughly equally wrong.
You sure the cams are timed up right ? maybe its better when hot because of the variable valve timing tensioner changes the cam timing once the cat / engines hot.

I would suggest taking the dipstick out with the engine running, check for excessive air blowing out - that should tell you if its bottom end or top end related.

Also you said you rebuilt the engine - did you reuse the stock pistons & rings or fit new ?
If you refitted the stock parts did you keep all the rings & piston with the specific bore they came from ?
Have you had the block bored or honed etc ? If so what piston / wall clearance did you specify ?

Hope you sort it mate.

 

[DaNnY_LaD]

Hi graham...

When the belt failed it only bent 9 valves which was all the exhaust and 1inlet...which John checked them all over and he rebuilt it...as for the bottom end there's was no damage apart form the crank pulley and flange..

There was miner kiss marks on top of the Crown of the pistons and the engine turned over buy hand nicely and the top decks were requal...

so basicall the bottom end wasn't touch as it was the head that was rebuilt...i have updates rods in my bottom end which I fitted months back....

So basically take the run it from cold and take the dipstick out and feel for passing air? Tbh with the compression results I think my guage is **** tbh...

 

[grahams81]

The gauge should pump up, does it have a valve on the side to press to let the air out, if so check it it might be leaking and giving you false readings, i think i got mine from halfrods for about £15.

Doesn't sound like it's the bottom end then mate if its as it was running, i would maybe suspect the cam belt timing or the timing of the two cams with the chain.
When the engines cold the VVt advance or retards (can't remember) the non direct driven camshaft, this changes the valve timing and helps cold running / preheat the cat to improve its efficiency.

- that would explain the engine not missing when its hot.... maybe unplugging the VVT chain tensioner when its cold to see if it runs ok - i think but im not 100% sure with the VVT unplugged the tensioner should go to the "engine fully warmed up" position. Thats a quick trial to help diagnose if its cam timing related.

Did you reface the valve seats ? If so you need to be careful the max dimension of valve length onto head is not reached - if it is close then the valve once seated is further into the head / closer to the camshaft / the lifter could be bottoming out once full of oil and holding the valve open slightly... Just an idea..
There are dimensions in the Workshop manual i bought but im away on hols at the moment mate so can't getyou them.

 

[ibizacupra]

the first valves to hit on mine were the centre inlet valves....

 

[DaNnY_LaD]

John checked the inlets and said they were fine...

So to night should I unplug the vvt from cold and see how it is?

 

[DaNnY_LaD]

Ive done 70miles in the car now and its still the same...and got the following codes 16684,16688,16717

 

[grahams81]

Still the same after unplugging the vvt ? And bill do you mean the centre inlets weren't seating ?

Did you have the valve seats cut dan ?

 

[CupraMVR]

No valve seats were not cut or refaced . just the valves lapped back in.

 

[DaNnY_LaD]

Should I unplugged the vvt from cold or when its hot?

 

[BBoy82]

I take it theres no white gunk in the top of the oil filler plug, and all fluid levels are ok? i.e head gasket is sealing properly?

 

[DaNnY_LaD]

So really I'm 100psi of the target for compression....il try the vvt tonight and the. Get it red hot and then do a compression test...

 

[grahams81]

Dan, I would unplug the vvt from cold and see how it runs from cold, if it runs better than its gotter be the timing between the two cams or the main timing belt.

As you've said the valve seats weren't cut then thats that idea out the window, personally i would take the rocker cover off and check all the timings.... If that looks perfect then i would be tempted to look at the lifters.
Of course all this speculation is down to the low compression figures, i would be tempted to buy another compression tester just to eradicate this as the problem could be electrical .....
Good luck mate,
Graham.

 

[DaNnY_LaD]

Tryds what you said graham and it sounds worse with the vvt unplugged ...And also checked the Dipstick and there no air escaping out of it...theres a moderate amount of course due to the crank spinning round...

So i need to get a compression test done first really then take it from there...Should i do the test cold or hot..
As its wierd soon as you start it it will run lumpy then take it 5mins up the road it gets better and better...

There's No Smoking ect when driving it but im getting a knock sound from the Gearbox side but only when its cold....If i quickly rev it so it just pics up it will got ''KNOCK'' but doesnt increase with revs and so on...Im thinking DMF personally