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Engine Out Of Tune, Head Gasket Gone?


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Hi all

I would be very grateful if i could pick your minds as mine is useless. My engine was running a treat as Andy Spencer could testify, then two days ago it started demonstrating the above syptoms. 4 days ago i started mending the clutch cable then two days ago i left the bonnet open whilst it rained. I thought this was the cause but i dried it down and gave it the hair dryer plus i gave it a run for half and hour today and it hasn't made a difference. The engine is firing on all 4 as i have taken each lead off, but i think it is a few horses down on power to. I did take 2 HT leads off doing the repairs but they are back on ok. I also took off the trumpets and disconected a lead from the throttle body. My concern is head gasket but how can i tell apart form possibly oil in the water? Hopefully it only needs Spark plugs like Tony Bs car but i doubt it. Many thanks chris

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If it is the head gasket there is a chemical you can add to the rad water that will change colour if exhaust gas is present to prove it.

 

Has the oil on the dip stick gone like cold coffee. if it is you have water in oil.

 

Is the oil level rising/ making oil as water mixes with it and loss of engine coolant.

 

When it starts up after being left do you get white steam from exhaust.

 

These are all tell tale signs of a head gasket gone.

 

Stephen

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As it happened after an engine soak I would look for engine sensor plugs that got wet. Can you plug in the laptop and check ECU readouts to confirm it is reading sensible values for the engine/ECU sensors. Get some compressed air on TPS, air temp, water temp plugs, then the hair dryer. Zetecs can also store water down the spark plug recesses which takes a while to boil off. Dry them out too.

 

Nigel

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Hi Chris

I'd be surprised if you've blown the head gasket given that its not overheated and no tinkering elsewhere has happened.

I'm going to be careful here as Steve's simple advice was best with Tony B (its so easy to overcomplicate things doing it blind on the internet) so take his advice first.

 

If all looks OK I'd suggest there's a possibility that your coolant temp sender is a bit loopy and may have been affected by the damp. Try disconnecting it first (on the water rail by the cap) and making sure the connection is dry and clean, then reconnect as it was reading fine when we connected the ECU to my laptop a couple of weeks ago. Shame you can't yet connect your laptop to see what its reading.

 

Do the same with the wire you disconnected from the TB's. Which one was it? I wonder whether the throttle position sensor has been disturbed?

 

I'll leave it at that as I'm working blind again and don't want to lead you down an incorrect route as I partly did with Tony B.

 

Worst case I may be up the M40 again soon and may be able to call and have a quick look with the laptop.

 

Also try Richard Hall at GBS - its his old car and he built it so he'll know it inside out and he's very helpful.

 

Best of luck.

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if its back firing then it is under fuelling.

Absolutely which is what makes me think its something to do with the coolant temp sender, would also explain lack of 'choke' (enrichment) on start up if its giving a falsely high reading to the ECU.

 

As ever though advice from others before is sound and should be explored.

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just a thought but have you checked the fuel for water. condensation will build up in the tank and drip and sink to the bottom where it will be sucked up. Have you either run very low or recently filled up. I once took the tank off a fiesta that was refusing to run properly and removed 1 litre of water which i can only assume came from dodgy fuel. There was a spate of this a year or so ago, i think it was on the news as loads of cars were ruined and had to claim off tescos etc.

 

hth

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Thanks everyone for your advice. I have checked the oil colour and it looks clean enough but did notice some bubbles on the dipstick. I have checked the tops of the sparkplugs and Ht leads which are dry. I have also cleaned and dried the sensor on the end of the water rail, as for water in the fuel i filled up about 3 weeks ago and it is on a quarter of a tank. I haven't run out but do run it down to 5 litres. I think my next step is to run a comp test, check the water for oil. Following that i think i will work out how to get my lap top connected to the ECU. cheers chris

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Chris - if all else fails I'll be up the M40 this week. I'll call you and we can plug mine in and see whats going on.

 

Dave at Emerald will tell you how to get your serial to USB adapter to work, its complicated, I remember a few people having trouble.

 

Cheers

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Went to Halfrauds on sat morning to get comp testers and couldn't get it to fit, seemed slightly to big, It says it fits all 14mm and 18mm spark plug ports. Could i be right in thinking that the ports on the zetec are 12mm?

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No a standard comp tester won't work as the plug recesses are too small to get the end into, even though the threads would work. Mine's a cheap push fit one, which makes testing a 2 man job but easy, and cheaper. Take the one you bought back to Halfords.

 

I will be up the M40 definitely soon. I'll let you know. In the meantime work on getting the laptop connected then we can work over the phone.

 

Cheers, Andy

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