overheating after retiming

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jc denton

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Just reset the valve timing & ignition timing on my celica. The engine seems to be running fine but now its overheating.

It wasn't overheating before so how the **** can can having the valve timing 10 degrees advanced cause it?

Any advice would be greatly appretiated.
 
Well however strange it may be may be as you have not done anything else and it has now started to overheat unless its a complete co-incidence it must be something you did.

Out of interst why did you change the settings ?
 
Sounds as if you've disturbed something else whilst working on it. Running a car with correct ignition timing will not cause it to overheat.
 
What if the ignition or valve timing is Just slightly out? Shurely it wouldn't cause overheating.

It only tends to get hot when under load (up hill, low revs), while parked I can rev the engine all I like & it dosn't get hot.
 
If you touched the water pump then there could be an air lock in the system and it needs bleeding,
 
Ive been doing some reading & apparently bad ignition timing can cause overheating & detonation.

My valve timing is now 5 degrees advanced which shouldn't cause a problem, but I don't have a timing light so who knows how accurate my ignition timing is...(I just rotated the distributor until I found a steady idle speed).

Thanks for the advice everyone, I'll post my results here when I get it sorted.
 
i dont think timing can cause an overheating problem ever (correct me if im wrong) if the timing is out the best case scenario is it has a very rought idle like a mis-fire, and worst case (if you didnt turn over the engine by hand first) i guess would be bye bye valves and pistons BANG!

i would have thought overheating maybe caused by a water leak or air lock as the others have said
 
Got an ignition timing light today & I think I see the problem. My ignition timing was sitting about 25 degrees advanced, but adjusting it back to the origional 10 degrees is not possable because it stalls the engine.

In short its impossable to get it right until I get the valve timing put back, its advanced by one tooth atm.

Starting to wish I hadn't messed with it.
 
You might have to do this in stages, adjusting idle bypass and idle mixture to bring up the idle speed when it's about to stall and the retarding the timing. Bit by bit you'll get the settings correct.

Does your car have a vacuum advance on the distributor? If so then disconnect the vacuum pipe at the dizzy end and plug it so that there's excess air cannot enter the manifold. The vac device on the dizzy can remain open.
 
OK, so I just had it to the garage to get the valve & ignition timing reset ( £118 ) & the mechanic said he couldn't understand why when all the timing marks where lined up the belt was half a tooth off... or why when he set the ignition timing to 10 degrees it runs as if retarded.

So I had the rocker cover off today to check the cam positions, there both bang on! but setting the ignition timing to 10 degrees causes it to run rough (like its retarded) & it still overheats but not so quickly.

The only way I can make it run properly is by setting the ignition timing 20 -30 degrees advanced, but it gets hot.

I'm at a loss to explain this.
 
Air lock maybe like they said? try running the car with the water cap off and see if there are any bubbles,

Does the car have some sort of cold start advance system on it?
 
Got it sorted!!

Pulled the thermostat out to counteract the overheating problem. Temprature still sneaks up a little when going up hill but mostly stable.

Advanced the ignition timing fully, about 30 degrees.

Shorted out the diagnostics connector so the computer can't interfere.

The check engine light is on now but its running better than ever.

Still don't know what was causing the overhheat though...
 
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Out of interst why did you change the settings ?[/QUOTE]


Just trying to squeeze a bit more power out of it. (Never noticed a difference).
 
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jc denton said:
Got it sorted!!

Pulled the thermostat out to counteract the overheating problem. Temprature still sneaks up a little when going up hill but mostly stable.

Advanced the ignition timing fully, about 30 degrees.

Shorted out the diagnostics connector so the computer can't interfere.

The check engine light is on now but its running better than ever.

Still don't know what was causing the overhheat though...
Click to expand...

This sounds a bit questionable to me.

Just because it's running better than it was before you attended to the timing (I don't use 'ever' as this word encompasses the whole of time;- past, present and future - in my quantum-physics-tarnished little mindset) doesn't necessarily mean it's running properly.
 
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It starts & it goes & (I'm possibly imagining it) but it feels more powerfull than before...
& in my mindset thats good.


No idea how long its going to last though.
 
I know how long its gonna last! Not very long!!

Just got back from work (30 mile or so on A roads) & it was starting to get hot again.


Apologies to anyone taking my advice from this thread.

Why the hell is it overheating? Water is cerculating so I don't think its the pump. I'd rather fix this than do an engine swap.


PS (post script): If you think you can fix it its on gumtree for £600, sell for £500. (When I say the bodywork is mint I mean MINT).
 
Took the thermostat out to help counteract the overheating! Fans are woking, coolent is circulating, no leaks, no air locks, temprature sneaks up when the engine is under load (up hill).
 
Water pump was shagged, replaced it & no more overheat, but the temprature is still fluctuating slightly.

Still can't get it running properly...sometimes its perfect othertimes it feels retarded.

Anyway, I'm fed up with c*****g about with it. Its now for sale.
 
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