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Old 5th August 2018, 21:41   #1
nomzamo999
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Default ZT 160 turbo help needed please

Hi all.
I've had my 160 a month now and I'm in need of a little advice.
When I bought it (cheap), it had a bit of a coolant leak, which I assumed was the head gasket. On advice I changed the inlet manifold gasket, which stopped the leak. However, before the gasket arrived, the engine developed a misfire and then hydro locked. When I changed the inlet gasket I also changed the spark plugs, and the misfire went away.
I took the car to Silverstone (700 mile round trip) for the British Grand Prix. The car got there lovely, but while I was there I ran the engine for a few hours to charge my phone and the short top hose burst. AA fixed it and I drove it home. As I drove home, I noticed the misfire was back.
When I got home I cleaned the plugs and shone a torch into each cylinder. All looked well, but to be honest I didn't really know what I was looking for. Since then I have changed both coil packs and both HT leads. Running is less lumpy, but still not right.
Here's where I need the advice. Could the hydro locking have bent a valve stem? I can't hear any tappetty sort of sounds; there's just a stutter on acceleration and a bit of lumpiness at low revs. The only other thing I can think of, if not a valve stem, is a damaged injector.
So, before I spend out on new injectors or take the head off, I'd like to hear your thoughts on what I should be looking at.
Thanks in advance.
Martin

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Old 6th August 2018, 09:49   #2
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Originally Posted by nomzamo999 View Post
I took the car to Silverstone (700 mile round trip) for the British Grand Prix. The car got there lovely, - - -
I don't sense any bent valves or such here.

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I ran the engine for a few hours to charge my phone and the short top hose burst.
Wouldn't it just charge directly from the battery? After a 300 mile run it would have plenty to spare.

The hose burst because the engine overheated. Did the radiator cooling fan not operate? It should have tripped on at 105C or so, before the hose burst. I suspect the loss of slow speed cooling has exacerbated the problems with the cooling system. Can you run the Demist Test?

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Old 6th August 2018, 10:00   #3
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Thanks. Cooling fan seems just fine. I think it's undeniable that running the engine for a couple of hours in 32C sunshine was a mistake. I'd only had the car a week and wasn't sure of the condition of the battery.
I'm sure I've damaged something, and I'm sure I can repair whatever it is. I just don't know enough to find out what the damage is.

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Old 6th August 2018, 10:18   #4
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What gap have you got on the plugs? 1.8Ts run best with the gap reduced to 0.6 - 0.7mm not the recommended 1mm.
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Old 6th August 2018, 11:25   #5
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Try a replacement boost solenoid first.
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Old 6th August 2018, 11:34   #6
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Sorry, I have to ask, what are the circumstances around the "hydrolocking"?
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Old 6th August 2018, 11:44   #7
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Sorry, I have to ask, what are the circumstances around the "hydrolocking"?
Hydrolocking is as i undertand the term when an engine either seizes or suffers catastrophic failure due to the ingress of a substantial volume of water in the cylinders. I can only imagine the OP has done this if they have gone through a flood/pool and the air intake has taken onboard a substantial amount of water.
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Old 6th August 2018, 12:28   #8
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Hydrolocking is as i undertand the term when an engine either seizes or suffers catastrophic failure due to the ingress of a substantial volume of water in the cylinders. I can only imagine the OP has done this if they have gone through a flood/pool and the air intake has taken onboard a substantial amount of water.
Yup, I know that, I was asking for an explanation from the OP.
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Old 6th August 2018, 12:46   #9
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Cooling fan seems just fine

Can you elaborate?
Is it a resistor controlled 2-speed?
Was it running all the while the phone battery was charging?


Questions, questions.

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Old 6th August 2018, 12:58   #10
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Quote:
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Sorry, I have to ask, what are the circumstances around the "hydrolocking"?
The inlet manifold gasket was leaking and allowed water into at least one cylinder. Overnight this built up to a level where the engine wouldn't turn over, due to water being much harder to compress than air.
This is only something I became aware of afterwards, so at the time I did exactly the wrong thing and kept trying until it finally cranked over and started.
That's why I was concerned about a bent valve stem: turning the engine over with an incompressible fluid in the combustion chamber, with nowhere to go, but out past a valve stem.

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