172 staring on 3 cylinders

[cliosrsikkk]

If I start my sport first thing in the day or a couple of hours after parking it up it will start on what sounds like 3 cylinders then after less than a minute or so it will change to all 4, any common problems or things to look out for? Could need a good service?

 

[MicKPM]

Are you sure its actually on 3 rather than just running rough? If its temp related I'd be tempted to get it looked at electrically first off and if all is well there go mechanically (ie Comp test)

Mick

 

[cliosrsikkk]

Sounds like its on 3, makes the car shake, its also using alot of water but no raising temps (according to the gauge anyway) and no mayo

 

[pearl172ph2]

My 52' 172 does this aswell. I was assuming it was a pinhole in a hose or maybe the water pump gasket leaking, but so far I have just been living with it..

Excessive vibrations at idle with my car, i put down to old engine/gbox mounts.

Does your idle start off high? around 1200rpm then slowly drop to under a 1000rpm over a minute or two? I was concerned I needed an IaCV as ive had random cut outs when slowing for junctions too.

 

[cliosrsikkk]

Only started doing it recently as it used to use no water at all, can hear water hissing its tits off thru the seal on the coolant bottle

 

[pearl172ph2]

Sounds like a new Screw cap is needed or at least a new seal if serviceable. Still doesnt explain your rough idle though.. Im leaning towards IaCV needing replacing/cleaning.

 

[Simon_16v]

Sounds like the pre-cat lambda sensor. When mine started on the automatic choke it would sound like it was on 3 cylinders and then once the choke turned off it would run sweet as a nut.

Any engine management lights?

 

[cliosrsikkk]

Engine light is on but has always been on due to decat

 

[cliosrsikkk]

Escalated to now sounding like its running on 3 under 10mph an throwing smoke out everytime I pull away

 

[Strettman]

possible head gasket failure? it would explain the smoke (burning oil?), water usage and misfire.

​thanks

 

[cliosrsikkk]

Its all white smoke, an running like a bag of dicks, its fubar

 

[Simon_16v]

Engine light is on but has always been on due to decat

Well you need someone with a diagnostics machine to clear the codes and see what comes back up.

Should only really have 2 codes, one for low efficiency cat (for obvious reasons) and second lambda sensor saying it's unhappy.

If you've code P0130 - O2 Sensor Circuit, it'll be your pre-cat sensor and will make your car run like a bag of nails whilst on the cold map

 

[cliosrsikkk]

Its shagged mate head gaskets gone cheers for the info tho

 

[Simon_16v]

Ahh right, sorry to hear the bad news but at least you've found out what your problem was