Drinking Coolant / Head Gasket / Emissions

xDParis64 said:

Well... Now my brakes are back to almost normal, I can return to this. I have booked an MOT for Thursday - to see if it'll pass emissions, but should it fail (it still has that odd misfire) I still have a few ideas, before I rebuild the motor.

It could be some of the following so I am looking for advice on how to test these in the best way possible ideally without £400 smoke machines or emissions testers.

Spark Plugs - I am going to take them out and get pictures of each one, one by one, to compare them and see if there is too much fuel / not enough / oil and or coolant etc

HT Leads - This I am not sure how to test without simply replacing them. - but may be worth cleaning the ground attached to the gearbox as that is connected through to the HT leads...?

Distributor cap - I am sure this won't be the issue - Because I replaced it about a year ago now, though I suppose I have been green-laning / off roading a few times since so it is possible dirt or debris got in there? I will go in and take a look.

Rotor arm - Again I think this is unlikely as like the previous one I replaced this about 12 months ago... But I am sure I will look into that when taking the dizzy cap off.

Distributor shaft play - Will check again.

Wiring & grounds - As mentioned I will probably remove the gearbox ground and some other grounds I can find to clean them and try again.

Vacuum lines - I will spray all the vacuum lines I can find with brake clean to see if I can find a leak (increase of revs).


If anyone has anything else I can check, please let me know before I spend ~£1500 on an motor rebuild as realistically I don't want to do that soon, eventually though

Click to expand...

xDParis64 said:

I THINK I FIXED IT! (Long post)

I took a look today before it started throwing it down and found a couple of things;

Firstly I took the distributor cap off to inspect for water ingress from greenlaning and found OIL inside the distributor cap, took the plastic seal off the rotor arm and it was cracked! Wiped everything clean to re-test and the misfire was gone! That makes a lot of sense now to why there was a misfire, once we did so I took the car back for an emissions test now there is no misfire... It still failed (sheet below)

View attachment 348809

This shows pretty much the same thing... No worries I thought worth a check - Got home checked the PScan and saw I can check fuel trims on there for the percentage of extra fuel or reduced fuel 100% being perfect / no added/reduced fuel

Checking this it showed about 115% - 118% which is wayyy off (Should be about 98% - 102%) this confirms that there is too much air being read by the O2 Sensor - I was able to confirm the O2 Sensor is probably fine because it reacts quickly when revving / creating vacuum leaks.

So following this I removed the EVAP hose to the inlet manifold and the trims did not change - So I thought fine I will let it cool down and try to find some leaks in the headers (I was not very optimistic) so after about 2 hours in the rain I believed it was cooled down and tested with my hand - It was.

Sprayed the headers with loads of soapy water to start it - had my assistant (missus) cover the tail pipe to increase back pressure to make bubbles more obvious.

I found 2 Leaks. (1 Obvious but very small and the other big but very hard to spot.)
View attachment 348810View attachment 348811
Sorry for the Horrid pictures I could not for the life of me get pictures before the exhaust got too hot and the bubble instantly boiled away.

But! I tightened the bolts on the headers literally about 1/15th of a turn on 2 bolts and checked again - no bubbles at all on either parts of the headers - So I checked the trims which were about ~105% that is between 10 and 15 percent decrease in extra fuel.

I thought that was still a little high so still a leak, this was later confirmed that when the car warmed up the trims dropped to 100% PERFECT!

That means the exhaust had expanded and sealed itself removing the leaks: View attachment 348812

So with that I have ordered a new gasket to fit and seal the headers.

Oh yeah there is also a couple holes in the Mid pipe to back box: - Ordered a new one of those
View attachment 348813

Thank you for everyone's help! Hopefully I can get it tested again and MOT'd before the meet! Super Hopeful

Click to expand...

andyfreelandy said:

Let's hope the leaks are the issue. Don't think yours has the 2nd O2 sensor so exhaust shouldn't make a difference.

Click to expand...