Overhaul/ Top Overhaul

[Stepper]

What is the different between overhaul and top overhaul?

 

Can someone help in listing out what is done during overhaul/ top overhaul?

 

Will gladly appreciate all inputs.

[Vtim]

Top overhaul means overhaul the top portion of the engine (normally without removing the engine), eg, Head gasket, valves, tappets, piston-ring etc..., overhaul nomally means the whole engine remove from the engine compartment, strip naked & replacing any faulty parts that cannot be reach by Top overhaul.

 

Top overhaul can be done on inline (straight) & V block engine but not the boxer (horizontal-opp) engine.

Edited October 17, 2002 by Vtim

[Evillusion]

Sorry for bumping this thread up.Have any of you guys done a top overhaul before? Whats the cost of it being done on SG? My car reaching its 10th yrs next yr and most prob will be prolonging the coe. Had radiator problems for a few weeks but mech says engine still okay. Just in case things get worst better to know the numbers before i take the coe plunge. TYI.....

[Kb27]

Sorry for bumping this thread up.Have any of you guys done a top overhaul before? Whats the cost of it being done on SG? My car reaching its 10th yrs next yr and most prob will be prolonging the coe. Had radiator problems for a few weeks but mech says engine still okay. Just in case things get worst better to know the numbers before i take the coe plunge. TYI.....

 

One of the worst case would be engine gasket overheat and leak coolant.

You can sometimes see white smoke coming out of old lorries/vans, that's the gasket problem, engine burning coolant.

Cost to replace will probably be a couple of thousand dollars or less.

 

If you have an interference engine with timing belt, make sure the belt is changed at regular interval. Otherwise, damaged conrods, bent valves, etc can result - a few $Ks to replace and make right.

 

As for needing a top overhaul, I think there's no need, unless you want to rectify a fault, like to replace a leaking gasket.

[Evillusion]

One of the worst case would be engine gasket overheat and leak coolant.

You can sometimes see white smoke coming out of old lorries/vans, that's the gasket problem, engine burning coolant.

Cost to replace will probably be a couple of thousand dollars or less.

 

If you have an interference engine with timing belt, make sure the belt is changed at regular interval. Otherwise, damaged conrods, bent valves, etc can result - a few $Ks to replace and make right.

 

As for needing a top overhaul, I think there's no need, unless you want to rectify a fault, like to replace a leaking gasket.

thanks......thinking of decarbonising the cylinder head and lap the valve seat after i renew the coe. 10 yrs of use there will surely be built up carbon and valve seat wear and tear. Yes i do the routine maintenance every 10k km but i think even with preventive maintenance there will be a time when it wont be enough. Last time i rode my cbr when i do maintenance they will visually check the valve seat......after 4 yrs of abuse can see a bit of dark patches around the seat and the mech says still okay but got slight leak around some valve seats. Didnt do it as i sold the bike a few month later.... Edited July 1, 2017 by Eviilusion

[Kb27]

thanks......thinking of decarbonising the cylinder head and lap the valve seat after i renew the coe. 10 yrs of use there will surely be built up carbon and valve seat wear and tear. Yes i do the routine maintenance every 10k km but i think even with preventive maintenance there will be a time when it wont be enough. Last time i rode my cbr when i do maintenance they will visually check the valve seat......after 4 yrs of abuse can see a bit of dark patches around the seat and the mech says still okay but got slight leak around some valve seats. Didnt do it as i sold the bike a few month later....

[Evillusion]

I highly recommend the Redline SI-1 cleaner for decarbonising. Just drop 1 bottles in the petrol tank and let it do the work.

Maybe repeat 2x.

I've used a bit only and found the spark plug carbon was much softer and able to scrap off by fingernail.

Without the cleaner, the carbon was black hard.

 

Before I scrapped my van at 16 yrs due to COE, I had only replace the top cover due to gasket leak.

Otherwise, overhaul is not really necessary imo.

thats what acetone do too! Edited July 1, 2017 by Eviilusion

[Mkl22]

A proper top overhaul also involves changing valve stem seals. For a typical engine the oil burning mainly comes from worn valve stem seals. Unless you have the wonderful vw Audi engines which burn oil from poor piston ring design. To burn oil leaking from the piston rings the mileage must be quite high, maybe 300-400k

[Kb27]

Our COE system doesn't encourage to keep car, no matter how young or old.

 

I'll say budget around $5k for any repairs and forget about top or engine overhaul.

 

Repair when needed. If not needed, no engine trouble, don't splash the money trying to make it back to "new".

COE will end its life anyway, no matter how "new" your engine is.

[Mkl22]

Our COE system doesn't encourage to keep car, no matter how young or old.

 

I'll say budget around $5k for any repairs and forget about top or engine overhaul.

 

Repair when needed. If not needed, no engine trouble, don't splash the money trying to make it back to "new".

COE will end its life anyway, no matter how "new" your engine is.

Depends on what car! Some are worth keeping

[Ahbengdriver]

Change the head gasket, valve  seals, valve cover gasket?  these are the primary wear n tears

[Roh96]

A proper top overhaul also involves changing valve stem seals. For a typical engine the oil burning mainly comes from worn valve stem seals. Unless you have the wonderful vw Audi engines which burn oil from poor piston ring design. To burn oil leaking from the piston rings the mileage must be quite high, maybe 300-400k

 

What are the symptoms of worn valve seals? white smoke from exhaust?

My car starts to consume EO, mileage 180K. I intend to renew COE but like to know what is the damage to fix this. Other than this, the car drives well.

[Mkl22]

What are the symptoms of worn valve seals? white smoke from exhaust?

My car starts to consume EO, mileage 180K. I intend to renew COE but like to know what is the damage to fix this. Other than this, the car drives well.

 

yup, oil burning.. the car to see this easily will be a BMW E90 320i.

 

but it depends on what car it is.

[mrtay]

I did the full overhaul for 3.3 k for my 2.4 engine. that includes

piston ring 

overhaul gasket

air fuel sensor

o2 sensor

water pump

timing chain sprocket 4

timing chain 

timing tensioner

main bearing

conrod bearing

balance shaft

fan belt

iridium plugs

engine oil

geaarbox oul

coolants

 

what do u guys think?

[QQDreamer]

I did the full overhaul for 3.3 k for my 2.4 engine. that includes

piston ring 

overhaul gasket

air fuel sensor

o2 sensor

water pump

timing chain sprocket 4

timing chain 

timing tensioner

main bearing

conrod bearing

balance shaft

fan belt

iridium plugs

engine oil

geaarbox oul

coolants

 

what do u guys think?

 

 how much?

[mrtay]

how much?

3.3k

[CMH80]

Just want to ask if anyone have any idea:

Engine overheat and do a overhaul. After which still monitor the water level on and off. Some say is normal for water level not to be so efficient after overhaul as engine skim will like that cause the clearance thinner. some told me it is not normal. However , water temperature remain as normal just at time to time did top up water. Any comments?

[Beregond]

26 minutes ago, CMH80 said:

Just want to ask if anyone have any idea:

Engine overheat and do a overhaul. After which still monitor the water level on and off. Some say is normal for water level not to be so efficient after overhaul as engine skim will like that cause the clearance thinner. some told me it is not normal. However , water temperature remain as normal just at time to time did top up water. Any comments?

yes some time that will happen. u need top up coolant more often then last time before overhaul