Piston replacement on MPS

[JaiLai]

I have a 2011 Mitsubushi Pajero Sport, it has about 250K on the clock.

 

I've recently put it in to get the A/C unit changed out and now they tell me that the pistons need changed at a cost of 7K each ( x4 ). Is this normal for a car of this age with this mileage on the clock? i thought to confirm pistons need changed out it would require measurements taken? is it unusual that all 4 would need replaced at the same time or must they be changed as a 'set'?

 

I'm always suspicious about what they suggest to change, they also reckon they need to keep the car a week, which seems excessive....

 

Any advice / opinions would be appreciated by someone with knowledge.

 

Thanks.

[Kwasaki]

I would asked them what is the bores condition. 

Unless they have check bore wear don't see why they would say that.

[JaiLai]

Yeah, thanks for that, i'm sure it would require stripping and inspection before making a decision to replace. As mentioned i find it suspicious they can come to this conclusion without inspection....

 

I guess one would just expect to see scratches and scoring etc if they need replacement?

 

Thanks again.

[Techno Viking]

Ask them what the compression readings are.

 

[Anythingleft?]

You would take measurements of the pistons and there will be an acceptable wear limit-tolerance for that particular model of engine
Added to that if they replace the pistons and rings they would need to hone the bores to do a proper job. As for changing them all out... if it was a single piston failure with not many miles on the engine yes change the defective part, if its due to wear and tear causing a loss of compression due to high miles then it's safe to say all pistons would of worn equally so replacement would be all at the same time



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[JaiLai]

5 minutes ago, Anythingleft? said:

You would take measurements of the pistons and there will be an acceptable wear limit-tolerance for that particular model of engine
Added to that if they replace the pistons and rings they would need to hone the bores to do a proper job. As for changing them all out... if it was a single piston failure with not many miles on the engine yes change the defective part, if its due to wear and tear causing a loss of compression due to high miles then it's safe to say all pistons would of worn equally so replacement would be all at the same time



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Thanks for the info, appreciated.

 

In your opinion, would you says it's normal or not to change pistons on a car of that age with that mileage?

 

Thanks.

[Anythingleft?]

Thanks for the info, appreciated.
 
In your opinion, would you says it's normal or not to change pistons on a car of that age with that mileage?
 
Thanks.

Hard to say categorically but I would be looking at new rings and honing the bores if the measurements were okay, high mileage is normally glazed bores causing a few issues
How did they come to this conclusion? It seems pretty random.. do you have any faults that you are aware of? You obviously never took it in for this..

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[JaiLai]

3 minutes ago, Anythingleft? said:

Hard to say categorically but I would be looking at new rings and honing the bores if the measurements were okay, high mileage is normally glazed bores causing a few issues
How did they come to this conclusion? It seems pretty random.. do you have any faults that you are aware of? You obviously never took it in for this..

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I don't know how they came to this conclusion, it was in the change out the Aircon unit which is logical as it was not performing and when stripped you could see the wear / damage so i have no problem with the cost involved with that.

 

There is no difference in performance, occasionally it requires the filter changed as it splutters a little bit about 80kph and pumps out a bit of black smoke ( not excessive ). I normally have it in every 4 months or 15K for an oil change.

 

Thanks.

[Anythingleft?]

I don't know how they came to this conclusion, it was in the change out the Aircon unit which is logical as it was not performing and when stripped you could see the wear / damage so i have no problem with the cost involved with that.

 

There is no difference in performance, occasionally it requires the filter changed as it splutters a little bit about 80kph and pumps out a bit of black smoke ( not excessive ). I normally have it in every 4 months or 15K for an oil change.

 

Thanks.

Personally I would not trouble myself with it, have the aircon fixed and continue with the regular services. Sounds like they are drumming up business

Believe me you would know if you needed engine repairs of that nature......

 

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[JaiLai]

3 minutes ago, Anythingleft? said:

Personally I would not trouble myself with it, have the aircon fixed and continue with the regular services. Sounds like they are drumming up business

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yeah, thanks for that.

 

What would be the worst thing that could happen anyway, the pistons fail and need replaced anyway or is it likely they'd damage other components?

[Techno Viking]

1 minute ago, Anythingleft? said:

Personally I would not trouble myself with it, have the aircon fixed and continue with the regular services. Sounds like they are drumming up business

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I personally would not consider mechanical advise from an AC shop nor let them tears my engine to piece and rebuiild it.

 

OP. if you have any doubts take it to the Mitsu dealer and tell them the story and ask them to look at it and offer their opinion.

[JaiLai]

4 minutes ago, Techno Viking said:

I personally would not consider mechanical advise from an AC shop nor let them tears my engine to piece and rebuiild it.

 

OP. if you have any doubts take it to the Mitsu dealer and tell them the story and ask them to look at it and offer their opinion.

A/C is getting changed at Mitsu dealer, it's them that's telling me the pistons require changing....

[Anythingleft?]

yeah, thanks for that.
 
What would be the worst thing that could happen anyway, the pistons fail and need replaced anyway or is it likely they'd damage other components?

Hypothetically you could scrap the engine in various ways
Just for your own peace of mind ask them how they came to this conclusion, that would be my first line of questioning

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[Techno Viking]

5 minutes ago, JaiLai said:

A/C is getting changed at Mitsu dealer, it's them that's telling me the pistons require changing....

Ohh.

 

Well ask them to substantiate their claims.

[JaiLai]

2 minutes ago, Anythingleft? said:

Hypothetically you could scrap the engine in various ways
Just for your own peace of mind ask them how they came to this conclusion, that would be my first line of questioning

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Yeah, will do.

 

Basically without inspection they cannot tell whether they need replaced or not, right?

 

I'm working at the moment but will be back mid June, i'll pop in and find out what the deal is then.

 

Thanks for your help.

[Techno Viking]

Assuming its a 2.5 a full aftermarket set of pistons, rings pins and locks can be had for 8,000 bath. import taxes will be approx 30%

 

http://www.ebay.com/itm/HYPATEC-PISTON-MITSUBISHI-TRITON-4D55-4D56-TURBO-ALFIN-INSERT-GALLERY-COOLING-/151401552463

[Anythingleft?]

Yeah, will do.
 
Basically without inspection they cannot tell whether they need replaced or not, right?
 
I'm working at the moment but will be back mid June, i'll pop in and find out what the deal is then.
 
Thanks for your help.

Without stripping the engine they can only guess at what might be happening inside but no they need to access the parts and do visual inspections and measurements. Which would only be done if you had problems in the first place by the way

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[commie]

33 minutes ago, JaiLai said:

 

What would be the worst thing that could happen anyway, the pistons fail and need replaced anyway or is it likely they'd damage other components?

Depends. Anything can happen, from burnt piston to damaged crankshaft to destroyed cylinder block.How they came to this conclusion is another thing, oil consumption/burn, compression, power output, knocking? Usually these are good enough reasons to take cylinder head off and check further. And if it's serious enough to change pistons nobody sane would do it without rebuilding the whole engine.

[transam]

Is it burning oil..........?

 

Does the engine run as smooth as usual.......?

 

Any new slap sound from the engine........?

 

Is there BLUE smoke coming out the tail pipe.....?

[JaiLai]

1 hour ago, transam said:

Is it burning oil..........? little bit of black smoke ocassionally

 

Does the engine run as smooth as usual.......? yes, no difference

 

Any new slap sound from the engine........? not that i can notice

 

Is there BLUE smoke coming out the tail pipe.....? no

 

[transam]

5 minutes ago, JaiLai said:

 

Then tell them to bugger off....

[Techno Viking]

lol, Black smoke according to one poster here I read in another thread indicates worn pistons !!

[Kwasaki]

3 hours ago, JaiLai said:

Is it burning oil..........? little bit of black smoke ocassionally

 

Does the engine run as smooth as usual.......? yes, no difference

 

Any new slap sound from the engine........? not that i can notice

 

Is there BLUE smoke coming out the tail pipe.....? no

There ya go nothing but a con.  

[canthai55]

3 hours ago, Techno Viking said:

lol, Black smoke according to one poster here I read in another thread indicates worn pistons !!

Black smoke - unburnt fuel. Blue smoke - burning oil. White smoke - water and/or antifreeze

[Techno Viking]

6 hours ago, canthai55 said:

Black smoke - unburnt fuel. Blue smoke - burning oil. White smoke - water and/or antifreeze

Post #42 by this fella who claims he has a Mechanics degree.

https://www.thaivisa.com/forum/topic/984467-just-a-small-chassis-but-beautiful-female-mechanic-wowing-the-boys-in-korat/?page=3#comment-11918665

[transam]

You must ask them the reason for piston change and let us know..

 

That job would take a long time as it is a complete engine tear down. It is normal to have a re-bore if pistons are changed, using +30th over size pistons..

[Kwasaki]

19 hours ago, Techno Viking said:

lol, Black smoke according to one poster here I read in another thread indicates worn pistons !!

Then all diesel engine drivers in Thailand beware. 

[Kwasaki]

2 hours ago, transam said:

You must ask them the reason for piston change and let us know..

 

That job would take a long time as it is a complete engine tear down. It is normal to have a re-bore if pistons are changed, using +30th over size pistons..

These did the job on my Ford Mk1 Consul,

 

http://www.cordsduaflex.com/whycords.html

 

Took the plugs out dropped the sump, pulled pistons, installed the new rings, they supplied ring compression tool which enabled piston re-entry to cylinders.

Fitted new big-end shells while l was at it, Weekend job. 

Sold it some three years later still running fine.

 

 

[Anythingleft?]

These did the job on my Ford Mk1 Consul,
 
http://www.cordsduaflex.com/whycords.html
 
Took the plugs out dropped the sump, pulled pistons, installed the new rings, they supplied ring compression tool which enabled piston re-entry to cylinders.
Fitted new big-end shells while l was at it, Weekend job. [emoji106]
Sold it some three years later still running fine.
 
 

I think he may of been referring to the more time consuming job of boring, honing the block not just fitting new rings from the underside.....

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[Kwasaki]

2 minutes ago, Anythingleft? said:

I think he may of been referring to the more time consuming job of boring, honing the block not just fitting new rings from the underside.....

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Yeah for sure l was just referring to a quick- fix job l did to a worn Piston/ bore related problem.