Vehicle overheated, oil change?

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Tswerie
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Vehicle overheated, oil change?

Post by Tswerie »

I drive a 2010 vw polo 1.6 tdi 310 000kms.

My vehicle overheated a few times (warning light only not steam overheated). The waterpump was replaced & doesn't overheat anymore.

1)But now when I drive and the engine reaches optimal temp I hear a knock (ping) when the engine revs are below 1200rpm and above 1800rpm.
The knock or ping is not there when the engine is cold.
1.a)Any advice, cambelt or oil change needed?

2) the engine was very quiet up to then, now it sounds like a loud, old diesel engine.
2.a) any advice?

Thanks

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Callum229
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Car Model: Jetta MK5 TDI DSG Highline
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Re: Vehicle overheated, oil change?

Post by Callum229 »

If it's very loud, something is seriously wrong.

Maybe loud lifters? How long did the overheating occur for?

Overheating shouldn't affect cambelt. An oil change may be good and worth a try.

Any smoke from the exhaust? Any coolant or oil loss?

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2007 VW Jetta MK5 1.9 TDI DSG,

Mods: Simple EGR delete, LED interior set up, LED rear footwell lights, LED Puddle lamps, LED Doorhandle illumination, LED License plate lights, LED Boot lighting.

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Tswerie
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Re: Vehicle overheated, oil change?

Post by Tswerie »

On start up grey smoke. Coolant lost too.

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missioner
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Car Model: '87 MK1 Golf Citi

Re: Vehicle overheated, oil change?

Post by missioner »

Sir you have hurt your diesel injectors.

It's also possible you have damaged the engine.

Diesels REALLY don't like getting warmer than need be. When the water pump failed you may have driven the car without coolant in the engine, it won't show hot on the gauge because there isn't any water to transfer heat to the temp sensor.

The heat will cause pistons to swell and score the cylinders (heat seize) that will later become a knock. Another thing that happens is the injector tips (PD's are direct injection, Google this) get hot and become distorted. This messes up the spray patterns and the tips leak and don't atomise the fuel properly any more. The droplets of fuel don't detonate right and can also become a knock.

The first issue will eat the prison rings and soon the car will produce blue smoke that smells oily. The second will produce grey or whitish smoke and it will have a sharp burn on the throat.

This is also provided that the turbo didn't implode and run the sump dry and cause bearing failure.

Dude the short version is that your car now needs lots of money. Be careful when buying an import motor ( if that's your choice) to many small variations in PD motors that can cause you to have issues. Get the same variant or get someone who knows their "business" to do the swap.

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Tswerie
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Re: Vehicle overheated, oil change?

Post by Tswerie »

Thanks for the comprehensive advice.
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