K series query - MGJohn?

[Sebastienclement]

Hi all,

Sorry this isn’t a 75 related question, but I’m sure there a folk around here who are au fait with the 1.4 k series.

Someone I know has one of these in a ZR. Recently purchased with 60k miles on the clock - a nice one owner vehicle. Slightly concerning issue with the engine while it’s warming up though...

It starts immediately from cold, and the oil light goes out immediately (interestingly enough, the light that lingers for a couple of seconds is the battery light... may be relevant). From cold the engine sounds lovely, with no top end noise other than the usual k series rustle. When the temp gauge just begins to lift off the bottom of the gauge the running becomes particularly lumpy (enough to feel it ‘chugging’ through the gearstick. At this point the car sounds positively awful from outside. There is definitely noise from the auxiliary belt, but I have a little suspicion that there is also bad engine noise too.

When it’s doing this is it particularly easy to stall, And takes a good few seconds of cranking to start again, and will often hover at around 500rpm for a few seconds before it drags itself up to 1000rpm idle.

One the car is warmed up it runs lovely, is smooth, sounds like a normal k series and pulls really well for a 1.4. The only thing I have noticed is that putting anything electrical on in the car does seem to affect how smoothly it idles. The engine does not use any oil or coolant and the fuel economy is pretty good for a petrol engine (38ish brim to brim).

I have a 2 theories:

1. Piston slap while warming up that is not evident when stone cold or fully warmed.

2. Some auxiliary device (possibly alternator or a tensioner) that is failing and sounds horrendous at a particular temp range,

Any thoughts?

I will try and get a recording of how it sounds later, but in my experience my phone doesn’t actually represent audio that well when it records.

[trikey]

Have you reset the iacv Tim?

[Sebastienclement]

Originally Posted by trikey

Have you reset the iacv Tim?

No, since purchase it’s had an oil change, MOT and that’s it.

Having watched some YouTube videos it almost seems like it runs on 3 cylinders until it’s warmed up. Time for spark plugs and new leads maybe?

[admiralalcatraz]

Originally Posted by Sebastienclement

Hi all,

Sorry this isn’t a 75 related question, but I’m sure there a folk around here who are au fait with the 1.4 k series.

Someone I know has one of these in a ZR. Recently purchased with 60k miles on the clock - a nice one owner vehicle. Slightly concerning issue with the engine while it’s warming up though...

It starts immediately from cold, and the oil light goes out immediately (interestingly enough, the light that lingers for a couple of seconds is the battery light... may be relevant). From cold the engine sounds lovely, with no top end noise other than the usual k series rustle. When the temp gauge just begins to lift off the bottom of the gauge the running becomes particularly lumpy (enough to feel it ‘chugging’ through the gearstick. At this point the car sounds positively awful from outside. There is definitely noise from the auxiliary belt, but I have a little suspicion that there is also bad engine noise too.

When it’s doing this is it particularly easy to stall, And takes a good few seconds of cranking to start again, and will often hover at around 500rpm for a few seconds before it drags itself up to 1000rpm idle.

One the car is warmed up it runs lovely, is smooth, sounds like a normal k series and pulls really well for a 1.4. The only thing I have noticed is that putting anything electrical on in the car does seem to affect how smoothly it idles. The engine does not use any oil or coolant and the fuel economy is pretty good for a petrol engine (38ish brim to brim).

I have a 2 theories:

1. Piston slap while warming up that is not evident when stone cold or fully warmed.

2. Some auxiliary device (possibly alternator or a tensioner) that is failing and sounds horrendous at a particular temp range,

Any thoughts?

I will try and get a recording of how it sounds later, but in my experience my phone doesn’t actually represent audio that well when it records.

Maybe just give it a general check over, check your voltages on the battery. Check your auxiliary belt is tight.

Change the fuel filter and put in some Redex (other fuel cleaner available ) and see how that makes a difference.

[Sebastienclement]

Ok, so maybe I should actually go try my theory before bothering the internet.

Popped an HT lead off and started it - sounded like it normally does from cold... Bingo.

Checked all spark plugs, found one loose. Connecting everything back up, made sure all connections were tight.

Started it up - lovely and smooth. Let it warm up to temperature & none of it's normal behaviour.

We'll see how it behaves tomorrow & will try new coil packs and leads next if it plays up again.

Sent from my SM-G960F using Tapatalk

[Sebastienclement]

Originally Posted by Sebastienclement

Ok, so maybe I should actually go try my theory before bothering the internet.

Popped an HT lead off and started it - sounded like it normally does from cold... Bingo.

Checked all spark plugs, found one loose. Connecting everything back up, made sure all connections were tight.

Started it up - lovely and smooth. Let it warm up to temperature & none of it's normal behaviour.

We'll see how it behaves tomorrow & will try new coil packs and leads next if it plays up again.

Sent from my SM-G960F using Tapatalk

However the aux belt does sound a bit rough - of you load it up with any electrical it begins to sound squeaky / generally a bit rough.

Sent from my SM-G960F using Tapatalk

[Discofan]

Tensioner or idler pulley beginning to seize, alternator bearings?