Anyone here have any experience with the 1.4 16v engines?

[Tommy5150]

Hey guys,

A bit off topic here, wasn't sure where to posit it. I am having some issues with a VW golf mk5 1.4 16v, but it has the same engine as the Audi A2. Didn't see an A2 topic so I thought I'd ask here.

Had the timing belt tensioner bolt brake clean off while on the freeway, turned engine off straight away and just rolled onto a off ramp. Towed the car home. Pulled the rocker cover with cams and found about 4 rocker arms destroyed, pulled the head out and found all 16 valves bent, luckily no piston damage thank god. So got the valves changed and head checked. Found that 3 stems that the valves travel in where damaged so where changed, and also 3 hydrolic lifters where stuck in the head, they where welded out and holes repaired.

Got the head back, put it all together and am getting slight misfire, the engine runs quietly and smooth apart for the slight misfire, on high revs ok but on idle the revs keep dropping and nearly stalling. VCDS gives me no engine fault codes at all. So not sure what to do next or what to check.

I have re checked the timing numerous times and are certain everything lines up (all the timing marks) and used cam locks to lock both cams in place. Have done timing on these motors before never had any issues, totally stumped with this.

All four coils where changed about 3 month ago and are new. So I also think if coils where bad VCDS would give me some coil related fault codes no? I'm getting no timing related codes either.

I know you peps have a wealth of knowledge so I thought I would ask.

Much appreciated for any advice

[EuroxS4]

I would say you have a internal issue within the head possibly or maybe broken valve spring. Then again misfire would only occurs above 3k rpms in such a case. Given the fact that the head had massive damage I would put it that something is still not right inside the head.

[Tommy5150]

I would say you have a internal issue within the head possibly or maybe broken valve spring. Then again misfire would only occurs above 3k rpms in such a case. Given the fact that the head had massive damage I would put it that something is still not right inside the head.

Hey Eurox, Thanks for replying and helping.

I had the head done at a professional garage where all they do is repair heads. So valve springs are good. The guy said the head is good, had him check if it warped or anything, shaved it slighly and repaired the 3 lifters and 2 or 3 valve guides. The best I had the engine running, only had a very slight misfire in cylinder 1 only, and only about 8 times in about 5 mins. Had the car on for a while and was even putting it under load. Which was all fine. Main issue was that as soon as i let it idle (when the engine was warm) the revs dropped to about 400-500-600rpm and where unstable jumping like it wanted to stall. And not sure why it was only misfire in cylinder one when compression was around 12 bar in each cylinder pretty much exactly the same. Has me scratching my head but would love to find the cause and reason for this. When the car ran perfectly before this. Strange....

How would I got about testing the intake manifold for a leakage test to see if it is pulling in outside air on this 1.4 16v engine? Because a compression test on the cylinder just tests the cylinder/piston/valve no?

[EuroxS4]

I would do a leak down test or a running compression test and take a video to slow down the needle to get an accurate measurement. But honestly I think leak down test is your best option and will tell you the most.

For running compression test remove the schrader valve.

If you want swap plug and coil to diferent cylinders and see if it follow the plug or coil that will rule those components out.

I have also seen sheared keyway on the cam gear and crank gear. It looks like its all correct but in reality one or the other is moved.

[Tommy5150]

I would do a leak down test or a running compression test and take a video to slow down the needle to get an accurate measurement. But honestly I think leak down test is your best option and will tell you the most.

For running compression test remove the schrader valve.

If you want swap plug and coil to diferent cylinders and see if it follow the plug or coil that will rule those components out.

I have also seen sheared keyway on the cam gear and crank gear. It looks like its all correct but in reality one or the other is moved.

Can I do a running compression test with my standard SEALEY CT955 static compression kit? Does this kit have the schrader valve? Is that the silver valve on the bottom of the clock that holds the pressure in? I did run the static compression test on each cylinder and came back with about 12 bar in each cylinder with pretty much exact readings for all cylinders. But was thinking to do a smoke test on the intake manifold if I can get a line in somewhere on the 1.4 16v. Will move the coils around with the plugs and see what happens if the code moves. Might also check the MAF I believe is there on the left side of the intake manifold. To see if it's working I'll unplug it with the engine running. Strange thing is on this engine there are no screws holding the MAF in it just looks like it's clipped in there. I found it strange but having holes for screws but no screws there. But funny how this did not cause any problems before.

The sheared keyway I will check first thing tomorrow I know on the crank cog cog it's easy to see if it's there. But on the cam it's harder to see no? I have to remove the Cam cogs to see underneath don't I?

Really appreciate all your help in helping me figure this thing out

[TobiqueSlang]

If everything on the rebuild side looks good, a long shot, might be an issue on reassembly. I'm not familiar with this engine but I know the old 1.8L 16V engines were prone to vacuum issues so maybe something on that side could have a tear/crack in it from putting it back together thats causing it to want to stall at idle.
I'd do a smoke test on the system for sure if you're already planning on doing the intake.

[Tommy5150]

If everything on the rebuild side looks good, a long shot, might be an issue on reassembly. I'm not familiar with this engine but I know the old 1.8L 16V engines were prone to vacuum issues so maybe something on that side could have a tear/crack in it from putting it back together thats causing it to want to stall at idle.
I'd do a smoke test on the system for sure if you're already planning on doing the intake.

For sure gonna do a smoke test. Really took my time with reassemble to make sure everything is right and done by the Workshop factory manual. Didn't get around to it today. And would also like to do the running compression test to see how it behaves.

[Tommy5150]

Hey guys, Does anyone know if the throttle body gets stuck or goes bad will it throw a DTC? Is the Bosch Motronic ECU smart enough to return a DTC when throttle body does not operate smoothly?

I know it will on a Open / Short but will it if it's getting jammed or stuck on idle? Just thinking out-loud...

[EuroxS4]

Normally will throw a fault for sensor a or b depending how its failing. You can try an adaption and see what it does.

[Tommy5150]

Normally will throw a fault for sensor a or b depending how its failing. You can try an adaption and see what it does.

Hey Eurox, ok cool thanks. Did do an adaptation for TB twice didn't make a difference.

[EuroxS4]

Are you sure you dont have any vacuum leaks? Can you look at fuel trims with VCDS?? mvb 32.

[Tommy5150]

Are you sure you dont have any vacuum leaks? Can you look at fuel trims with VCDS?? mvb 32.

I will have time to check the mvb 32 maybe tomorrow or at latest on Friday. So will let you know what reading mvb 32 gives me. Thanks heaps

[Tommy5150]

Are you sure you dont have any vacuum leaks? Can you look at fuel trims with VCDS?? mvb 32.

Hey Eurox,

Ok finally managed to get some time and look at the golf idle problem again, engine doesn't run too bad but still getting slight misfire. Had a chance to look at the fuel trim mb32 like you said, pic attached.

Weird thing is it shows in the first box a value of 0%. Is that supposed to be 0? That pic was taken with engine running at idle. The second box shows a value of -18%. Is says in VCDS that value should be between -10 & +10. It that correct? Is that value right? What is it telling me if it's -18%?

Still haven't had a chance to smoke test the intake for leaks. But the weird thing was, when I ran the car for a bit got it up to temperature, then noticed all my coolant from the tank disappeared. But not sure where it went?? checked the oil was clean so it did not mix into oil, it didn't mix into the coolant either. Where else could it have gone? When I put the head back on before I used a new head gasket a good one. Torqued all the head bolts to spec and followed VW workshop manual for tightening procedure. So would love to know what happened to it where it went? Any ideas. Not leaking anywhere nor dripping. And the engine ran pretty good and smooth. Also pumped the coolant hose by hand when first filled coolant up to get all the air out and get coolant all the way into the engine. I thought if the water went into the cylinders it would be a lot of water and the engine would run allot worse than it is now.

One thing that I am thinking if the throttle body is possibly bad with no fault codes? On idle the revs where at about 550 - 650 but when I put my foot slightly on the accelerator just only every so slightly the revs would jump from roughly 600 to 1200 and back down. Up and down, Up and down pretty quickly. But I performed TB Adaptation and it said OK. There was no error performing that.

[Tommy5150]

ok so Managed to get another working throttle body (TB) today and tried to swap it over to see if it improves and fixes the problem... it did not work, same problem as before so problem is not in the TB. Looked at the MAF sensor as I had a look at the intake manifold pressure G71 and it was around 880mBar at idle and it seemed like it did not work. So I put a new one in and again did not fix anything. New MAF reading was about 450 mbar. It did run a bit better but still very low RPM 500 - 550 - 650. I then looked at the main Lambda before the Cat in the engine and it seemed to me like it was not working. In one of the measuring banks cant remember which one now showed the Lambda B1S1 at -25% that did not move. So I think the engine is running too rich. So ordered a new one should be in tomorrow will try it. And also am thinking I will pull the head tomorrow morning too just to see what it looks like from the inside and see whats happening if anything. I think I'm getting closer to finding the problem hopefully 🤞 this car is an absolute nightmare so far.....