Any - Diesel engine timing and temperature

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Tue 21 Aug 2012 18:30
Any - Diesel engine timing and temperature - mss1tw

Can the timing being slightly 'out' cause a diesel engine to run hot?

I ask as since the timing belt change recently my Berlingo has been getting 40 more miles to the tank and seems to run cooler!

I even phoned the mechanic to say thanks for doing a good job and he said it was out by a few degrees!

Just another error of the clueless moron that serviced it before I bought it...

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Wed 22 Aug 2012 10:31
Any - Diesel engine timing and temperature - dieselnut

If the timing is out the engine won't be running efficiently. The power output for a given amount of fuel will be less but it will still be burning the same amount of fuel. So a larger proportion of the fuel used will be turned into heat instead of usefull work. Perhaps Unthrottled or another expert will be along soon to give us a more technical explanation.

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Wed 22 Aug 2012 11:02
Any - Diesel engine timing and temperature - Peter.N.

I would agree, if the timing is retarded it will run quieter but be more difficult to start, it will also produce more heat and smoke and less power as explained above, if over advanced the efficiency won't suffer so much but it will be noisey.

One tooth out on the timing belt would produce either of these sets of symptoms. If it has an adjustable pump sprocket it could be altered slightly but its unlikely that it has been.

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Wed 22 Aug 2012 12:19
Any - Diesel engine timing and temperature - unthrottled

You have a 1.9 XUD IIRC. A lot of IDIs are factory timed slightly retarded. The reason being heat. The throat area to the pre chamber is subject to a large heat flux, and retarding the injection timing reduces the intensity of the heat flux so damage to the precups is less likely. A couple of degrees difference can make a noticeable difference to the performance on IDIs.

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Wed 22 Aug 2012 18:57
Any - Diesel engine timing and temperature - mss1tw

Thanks all, glad to know the science behind my specualtions!

I didn't ask if it had been advanced or retarded, but yes unthrottled you are right, those few degrees have made a big difference! It feels positively pokey now :-D and 440 miles to the fuel light rather than 400.

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Sat 25 Aug 2012 03:35
Any - Diesel engine timing and temperature - 1litregolfeater

Interesting topic.

I know nothing about diesels and currently live in fear of replacing the timing belt on an Astra 1.7 DTI soon.

The new belt will obviously sit slightly differently to the old one. Assuming it has timing marks, should I make it on the advanced or retarded side if I have to pick?

I'd assume the ECU would compensate for minor issues.

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Sun 19 Aug 2018 00:27
Any - Diesel engine timing and temperature - Mr Soprano
Cam timing on Diesel engines critical due to closeness of valves and piston at tdc. The belt should be replaced when engine is at top dead centre with cam sprockets and crank in fixed position so as to not be moved when re fitting replacement belt. Also best to change tensioner whilst your there, checking the bearings on other pulleys for noise/play etc. Don’t worry about changing the timing advanced or retarded the manufacturer will have the best position anything else could very much destroy an engine.
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Sun 19 Aug 2018 11:02
Any - Diesel engine timing and temperature - Surreydriver

Just to clarify. There are two "timings" now being discussed on this thread. "Cam" timing and diesel "injection" timing.

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Mon 20 Aug 2018 21:16
Any - Diesel engine timing and temperature - mss1tw

Good point surreydriver - although the only timing the poor old Berlingo will have to think about now is microwave timers, as it's now probably a pallet of food cans. :(

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