What does 'blown bottom end' mean?

ferry

Just curious but seen the term couple times now while car hunting,so what does it actually mean (I assume a new engine or rebuild) but what actually happens to cause it?

Oddly enough both cars I noted were older ( 01/02 plate Saab) is there a known issue with these cars?

Cheers
F

Richard53

I assume it means serious damage to crank, big end bearings etc, meaning a complete engine rebuild (or thereabouts).

However, I could think of much more amusing reasons for the phrase, mainly medical.

ferry

Richard53 wrote: »

I assume it means serious damage to crank, big end bearings etc, meaning a complete engine rebuild (or thereabouts).

However, I could think of much more amusing reasons for the phrase, mainly medical.

Ooooh,matron.....:D

forgotmyname

It means run away unless your a dab hand at building engines and swapping them over.

Retrogamer

As above.
Could also mean it's thrown a rod out the side of the engine block.

skivenov

He's dead Jim.

colino

It can range from the bottom end being rattly, the precursor to terminal failure as the crankshaft bearings, big end bearings and small end bearings are white metal coatings, designed to be sacrificial and are worn out before the crankshaft or gudgeon pins are wrecked.
It can also be an engine that has been completely abused and underfed oil where the piston rings wear out and you can hear the piston slap.
It can go as far as when the poor engine can take no more and,is as the picture above, but that is generally said to have "thrown a rod."
All of these examples are from neglect, lack of good oil, infrequent oil and filter changes. Saab and GM generally seem to have suffered en masse from this, ranging from when boyracers spend all their car money on the sound system than maintenance and the paper oil filters are ignored, either turning into leather and becoming useless or, even worse, breaking up and blocking the oilways. At the other end, Saab need good care enthusiastic driving on inferior oil seems to create a good deal of sludge in the engine and new owners are well advised to drop the sump, clean out the sump and oil pickup and do more frequent oil and filter changes.
Bad news is that few cars are worth repairing nowadays unless you diy and parts and reconditioners are disappearing.

bigjl

ferry wrote: »

Just curious but seen the term couple times now while car hunting,so what does it actually mean (I assume a new engine or rebuild) but what actually happens to cause it?

Oddly enough both cars I noted were older ( 01/02 plate Saab) is there a known issue with these cars?

Cheers
F

There can be lots of engine issues with turbo charged Saabs.

The main issue was use of semi synth oil and too long an oil change interval

The turbo positioning meant that the oil in the sump was hotter than expected and the use of semi synth meant the oil sludged up and bang.

Lots of info on this problem can be found on the specialist Saab forums.

The other issue with Saabs is they are treated as disposable by many. Even before the company closed down.

Most receiving no maintenancd other than MOT work. A shame as when maintained they are nice cars.

AdrianC

bigjl wrote: »

There can be lots of engine issues with turbo charged Saabs.

The main issue was use of semi synth oil and too long an oil change interval

The turbo positioning meant that the oil in the sump was hotter than expected and the use of semi synth meant the oil sludged up and bang.

Lots of info on this problem can be found on the specialist Saab forums.

^ this.

UKSaabs or SaabCentral will both have a LOT more info. In short, though, there have been several revised crank breather kits to reduce the risk of it happening, but the only real cure is removing the sump and cleaning it all out, then a shortened oil change interval with good quality full-synth. Worth it, though... It's really only a couple of years-worth of 9-5 and 9-3s that are at risk.

In practice, if it's already gone, then it's a full engine rebuild or replacement.