yact: how much damage would overheating do to the engine?

andylawcc

Lifer
Mar 9, 2000
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my friend's Passat (fairly old model, don't know what year) was overheated and the car cannot go over 30 mph. a mechanic checked it out and said the engine has to be replaced and would cost about $2500. my friend said forget since the car itself doesn't even worth $2500.
Doesn't an overheated engine just need a cylinder head swap? or the entire engine need to be replaced?
 

Mo0o

Lifer
Jul 31, 2001
24,227
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My parent's first car when they moved to America was real POS that overheated ALL the time. While driving my dad would have to pull over every so often to let it cool. Luckily we didn't have that car for very long. But to answer your question, i think it'll still run decently, we never had trouble getting to freeway speed or anything
 

crab

Diamond Member
Jan 29, 2001
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If hes been running it like that, I'm pretty sure it's shot. Coolant & oil possibly mixed, wore the hell out of everything. Possibly even bent rods from hydro locking, etc.
 

andylawcc

Lifer
Mar 9, 2000
18,183
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Originally posted by: crab
If hes been running it like that, I'm pretty sure it's shot. Coolant & oil possibly mixed, wore the hell out of everything. Possibly even bent rods from hydro locking, etc.

coolant and oil mixed? through the head gasket? where could both liquid come in contact?

correct me if i am wrong, if a car is "Hydro locked," it cannot be started at all?
 

CrackRabbit

Lifer
Mar 30, 2001
16,642
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When a car overheats it has a tendancy to warp the heads (especialy if it has aluminum heads and an iron block) when the head warps it creates gaps in the headgasket where oil and coolant can mix. When this happens the oil can't lubircate properly and the bearings in the engine wear prematurely.
How long has it been driven after it overheated? If taken care of soon enough your friend should be able to get at least a few more miles out of the car before it needs to be replaced.
You are correct, if hydrolocked the car couldnt start at all and you could possibly bend or break a piston rod. (Very bad stuff)
 

andylawcc

Lifer
Mar 9, 2000
18,183
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Originally posted by: CrackRabbit
How long has it been driven after it overheated? If taken care of soon enough your friend should be able to get at least a few more miles out of the car before it needs to be replaced.

Right after it overheated the car took a rest and re-started. The car still can move but it wouldn't go over 30 mph.
 

ggnl

Diamond Member
Jul 2, 2004
5,095
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Originally posted by: andylawcc
Originally posted by: CrackRabbit
How long has it been driven after it overheated? If taken care of soon enough your friend should be able to get at least a few more miles out of the car before it needs to be replaced.

Right after it overheated the car took a rest and re-started. The car still can move but it wouldn't go over 30 mph.

Could be loss of compression from a warped head/blown head gasket. How thorough was the mechanic in checking the car?
 

LordMorpheus

Diamond Member
Aug 14, 2002
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Hydrolocked . . . . correct me if I'm wrong (not really a grease monkey) . . . this is when you get non-combustibles in the cylinder (like coolant or water) so when the cylinder tries to make an upstoke it hits a solid and non-compressible barrier, causing all sorts of problems?

This is just a guess.
 

iamwiz82

Lifer
Jan 10, 2001
30,772
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Originally posted by: LordMorpheus
Hydrolocked . . . . correct me if I'm wrong (not really a grease monkey) . . . this is when you get non-combustibles in the cylinder (like coolant or water) so when the cylinder tries to make an upstoke it hits a solid and non-compressible barrier, causing all sorts of problems?

This is just a guess.

Yup, been there, done that :eek:

 

geno

Lifer
Dec 26, 1999
25,074
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You can warp/crack the head, or warp/crack the block, or a combination of the two. I'm sure that if run hot enough, you'll also damage bearings, and other bottom-end items....
 

crab

Diamond Member
Jan 29, 2001
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Originally posted by: andylawcc
Originally posted by: crab
If hes been running it like that, I'm pretty sure it's shot. Coolant & oil possibly mixed, wore the hell out of everything. Possibly even bent rods from hydro locking, etc.

coolant and oil mixed? through the head gasket? where could both liquid come in contact?

correct me if i am wrong, if a car is "Hydro locked," it cannot be started at all?

It doesn't need to be full of liquid...a small amount can do alot of damage. Maybe the proper term isn't hydro"locked", but it's possible.
 

V00DOO

Diamond Member
Dec 2, 2000
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His best option is to find an used low mileage engine from a junk yard. It's probably cheaper then rebuilting the engine.
 

andylawcc

Lifer
Mar 9, 2000
18,183
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Originally posted by: V00DOO
His best option is to find an used low mileage engine from a junk yard. It's probably cheaper then rebuilting the engine.

ROUGHLY how much would one of those VW's engine cost... I think it is the 2.0 GLi model, but I am not sure. (i am in LA, my friend is in San Diego)