Finally, a problem!

[Toby]

Hey dudes! Long time! Well for the past couple of years I've been running my SX daily and it's been reliable (apart from fixing a blown exhaust manifold gasket and replacing some leaking fuel lines). Hence my absence from this forum - I could focus on other things (hehe). Last week it started developing a seemingly simple problem: misfiring.

Aha! I thought. I've been through this before. It can only be:
- my very old spark plugs needing replacement, OR
- coil pack
Both simple, easy problems. So I replaced all spark plugs, started the car, and voila! Everything running smooth. That is, until I took it for a test drive. As soon as it warmed up, it started misfiring on idle. Nice and smooth over 2000rpm, but misfire below. Fine, I thought, coil pack it is! So I moved coil packs around, but to my surprise, the misfire remained on the same cylinder

I took it for another short test drive to get a better grip on the problem. Suddenly, the engine starts overheating! So I pull over and let it cool down. Within 4km of driving from home, all the water in the radiator is gone! I could hear the water escaping as steam. Managed to fill some water and drive it back home. When I got home, I could hear the steam escaping through the radiator cap, and the pipes were under pressure, but couldn't detect any leaks. Also the heater doesn't work.

So now my theory is:
- maybe thermostat is stuck, OR
- blown head gasket - though I can't imagine how, I drive it like a granny and it's stock

Any other theories? It will take a while but I'll slowly start eliminating issues one-by-one. Maybe run without the thermostat to check if it's that, then do compression test. Any theories and ideas welcome. Just thought I'd post, as a way of saying: "YO!"

[rat]

Hi Toby

I had a small hole in a water line under the intake mani and it did this (not the misfire) Bastard to get to.

Other wise head gasket could have gone.

Thermostat easy to check. Pull it out and drive without it or place it in hot water and see if it opens.

Water pump might not be moving the water?

[Toby]

Thanks rat, I'll check thermostat first, that's easiest.

[BigKriss]

Hey boet, howzit !
We meet you once ,then you dissapear !

Check the tail pipe for "crystals" Run it hot and check the tail pipe for steam or vapor. The fact that it misfires tells me water into the cylinder. Pull the plugs and again check for super clean plugs or "crystal" on the plug..
Thats my guess.

[Draco]

Hey Toby....Mr President....my bet is also HG, also check oil cap for white/cream coloured oil residue inside of cap, oil meet water...water meet oil.

[Ero_sennin]

Sounds like HG.
Missing water and no leaks, plus miss fire at low rpms. Thats what mine was doing when the water leaked into the cylinders. Although it was slow to disappear and I never saw any mayo anywhere, just the water getting less, until a much much later stage when more overheating occurred.
Do compression test but sounds like new HG and a skim is needed.

[Toby]

Head gasket confirmed. What a schlep

[godzilla]

hey guys glad u found the problem. Now my V6 hardbody i use for spining /drifting(if u can call what i do drifting lol) has a similar problem.not the missfire but the loosing water. i can drive normally on th eroad and alls well.but when i hammer and abuse the motoron the pitch the temp goes above half and i come off.my temp use to never go more than half . and when ive cooled down the radiator need atleast a litre or 2 of water. the plugs are good, thesere no milky oil,the oil caps clean, and i dont see any water leaks or marks of any water coming out. the exhast drips a few drops of water but my v6 was always doing that. so what els should i be cheking? cracked hidden pipes ?

[Draco]

Head gasket confirmed. What a schlep

Hey Toby....sorry man....

[wizard_600]

godzilla, any news or have you found the fault as yet, my ca 18 is doing the same, fine when i drive it normally like a white oke but as soon as i plant it it goes hot, i have replaced head gasket and pipes and everything else, i even torqued the head 160nm. no possibility of that going anywhere.

cheers

[godzilla]

I have yet to find the problem. i went to a drift only event and was doing good speeds and the temp behaved . but i havent had it spinning for longer times and slower speeds. i havent filled water in a wile but then again i havent driven it much in the last 2 weeks. so i have no idea. im still convinced its either a small tear in the head gasket or a fine crack in one of the heads that only realy opens up after getting really hot and abused.