2000 Daewoo Nubira

waedoo · Post by **waedoo** » Mon Sep 26, 2005 3:49 am

My neice has a 2000 daewoo nubira,she asked me to check out the car because it was difficult to start she also wanted the oil and sparkplugs replaced no big deal rihgt. Well not so fast.Essentially here is whats wrong this car.It has a very bad oil leak from the top half of the engine all of the sparkplug wells were filled with oil,I thought that it might be a valve cover gasket but that seems like an awful lot of oil to be coming from just a leaky valve cover gasket. The two hoses going to the throttle body were completely clogged with carbon and oil they came apart in my hand,new hoses are installed.Ichanged the oil and plugs, the car started/ran for a while but began to idle very badly and stall.I believe that there is a problem in the fuel injection sysytem,the car has a new fuel pump and filterso that can be ruled out as culprits.If I spray starting fluid in the intake the car will idle just fine until the starting fluid burns out ,if I continuously spray starting fluid in the intake I can rev the engine to 3000 to 4000 R.P.PM. ,But as soon as I stop with the fluid the engine either gasp's to keep going or flat out dies all together.One last thing.If I fight with it long enough and I mean a really long time it might hold an idle of about 750 to 850 R.P.M. but any attempt to open the thrttle kills the engine immediately and if becomes harder to start even with the stariting fluid.I am leaving some info. out because I can see that this is seriously turning into a book.But I hope that tihis will provide enough insight to anyone reading this post.All input,help,advice,quetions are welcome. P.S. while searching for information on this car I found this web see link below.THEY PROVIDE TECHINCAL/SERVICE MANUALS FOR FREE DOWNLOAD THEY HAVE THE SERVICE MANUAL FOR THE NEW DAEWOO/LACETTI BUT I DONT THINK THAT CAN HELP ME WITH THIS NUBIRA,THEY HAVE MANUALS FOR MANY OTHER VEHICLES AS WELL AS OTHER CONSUMER ELECTRONICS ITEMS,CHECK IT OUT. http://www.eserviceinfo.com/most_popula ... 11600.html
Service Manual free download,schematics,datasheets,eeprom bins,pcb

MMamdouh · Post by **MMamdouh** » Mon Sep 26, 2005 10:42 am

seems like the car hasn't been serviced for a long time.

It has a very bad oil leak from the top half of the engine all of the sparkplug wells were filled with oil,I thought that it might be a valve cover gasket but that seems like an awful lot of oil to be coming from just a leaky valve cover gasket

it is the cam cover gasket indeed... on those engines the oil keeps going into the S/P wells till they are flooded.

The two hoses going to the throttle body were completely clogged with carbon and oil they came apart in my hand,new hoses are installed

no idea what are those... anyways since you replaced them then you are OK. please elaborate more on them pipes... where do they come from?

also i would recomment a TB and IAC cleanup... the condition you discribed for the broken hoses (i think they are the EGR pipes) suggests that the intake is full of dirt.
http://www.daewootech.com/forum/viewtopic.php?t=2619

I changed the oil and plugs

did you change the oil filter and checked/replaced the spark plug cables?

I believe that there is a problem in the fuel injection sysytem

you can try a fuel injector cleaner or replace the injectors... start with the cleaner for the time beeing and if the problem presists and you are sure that every other thing is working fine then you will have to replace them. BTW don't rule out the air filter.

keep us posted with what you do.

waedoo · Post by **waedoo** » Tue Sep 27, 2005 12:15 am

mmamdouh wrote:seems like the car hasn't been serviced for a long time.

It has a very bad oil leak from the top half of the engine all of the sparkplug wells were filled with oil,I thought that it might be a valve cover gasket but that seems like an awful lot of oil to be coming from just a leaky valve cover gasket
it is the cam cover gasket indeed... on those engines the oil keeps going into the S/P wells till they are flooded.

The two hoses going to the throttle body were completely clogged with carbon and oil they came apart in my hand,new hoses are installed
no idea what are those... anyways since you replaced them then you are OK. please elaborate more on them pipes... where do they come from?

also i would recomment a TB and IAC cleanup... the condition you discribed for the broken hoses (i think they are the EGR pipes) suggests that the intake is full of dirt.
http://www.daewootech.com/forum/viewtopic.php?t=2619

I changed the oil and plugs
did you change the oil filter and checked/replaced the spark plug cables?

I believe that there is a problem in the fuel injection sysytem
you can try a fuel injector cleaner or replace the injectors... start with the cleaner for the time beeing and if the problem presists and you are sure that every other thing is working fine then you will have to replace them. BTW don't rule out the air filter.

keep us posted with what you do.

Hello Mmamdough thanks for responding.So it's the cam cover gasket.I will check/confirm your analysis and let you know.As to the hoses,they are rubber ,one comes off the valve cover and attaches to the air intake cover,the other smaller hose also rubber,comes from the cylinder head and attaches to a port on the throttle body.You are very correct about the dirt.The intake system is esxtremely dirty,it's more like an oil and grime mixture,it is caked and hardened on the underside of the throttle plate.I will remove the throttle body and clean it up.I did change the oil filter, I also used a fuel injection cleaner(prolong brand). I have not replaced the spark plugs cables but I believe they are ok,I will take a harder look though. Can the EGR valve or the O2 sensor cause this car not to start .

waedoo · Post by **waedoo** » Tue Sep 27, 2005 12:59 am

seems like the car hasn't been serviced for a long time.

Quote:
It has a very bad oil leak from the top half of the engine all of the sparkplug wells were filled with oil,I thought that it might be a valve cover gasket but that seems like an awful lot of oil to be coming from just a leaky valve cover gasket

it is the cam cover gasket indeed... on those engines the oil keeps going into the S/P wells till they are flooded.

Quote:
The two hoses going to the throttle body were completely clogged with carbon and oil they came apart in my hand,new hoses are installed

no idea what are those... anyways since you replaced them then you are OK. please elaborate more on them pipes... where do they come from?

also i would recomment a TB and IAC cleanup... the condition you discribed for the broken hoses (i think they are the EGR pipes) suggests that the intake is full of dirt.
http://www.daewootech.com/forum/viewtopic.php?t=2619

Quote:
I changed the oil and plugs

did you change the oil filter and checked/replaced the spark plug cables?

Quote:
I believe that there is a problem in the fuel injection sysytem

you can try a fuel injector cleaner or replace the injectors... start with the cleaner for the time beeing and if the problem presists and you are sure that every other thing is working fine then you will have to replace them. BTW don't rule out the air filter.

keep us posted with what you do.
Hello Mmamdough thanks for responding.So it's the cam cover gasket.I will check/confirm your analysis and let you know.As to the hoses,they are rubber ,one comes off the valve cover and attaches to the air intake cover,the other smaller hose also rubber,comes from the cylinder head and attaches to a port on the throttle body.You are very correct about the dirt.The intake system is esxtremely dirty,it's more like an oil and grime mixture,it is caked and hardened on the underside of the throttle plate.I will remove the throttle body and clean it up.I did change the oil filter, I also used a fuel injection cleaner(prolong brand). I have not replaced the spark plugs cables but I believe they are ok,I will take a harder look though. Can the EGR valve or the O2 sensor cause this car not to start . Idea Very Happy

MMamdouh · Post by **MMamdouh** » Tue Sep 27, 2005 5:26 pm

hi man... glad i could help

As to the hoses,they are rubber ,one comes off the valve cover and attaches to the air intake cover

that is the crank case breather... it transfers oil vapor to the intake so that pressure doesn't build up inside the engine... oil doesn't like rubber and it goes the other way too and after a while the rubber hose gives away and cracks.

the other smaller hose also rubber,comes from the cylinder head and attaches to a port on the throttle body

no idea what is it but it could be an auxilary hose for the breather or so... since you replaced it, you are on the safe side.

The intake system is esxtremely dirty,it's more like an oil and grime mixture,it is caked and hardened on the underside of the throttle plate

thats from the oil vapor comming from the crank case breather... all this dirt affects performance and specially idling, you need a throughout clanup job... use WD-40 and/or GUNK carb. cleaner along with the instructions i refered to earlier.

I have not replaced the spark plugs cables but I believe they are ok

for a fast test... turn the engine on in a dark night, pop the hood and watch for sparks flying from the wires... if any were detected then the wires are bad... if sparks doesn't show up that doesn't mena the wires are perfict... colud be something internal that doesn't leak.

Can the EGR valve or the O2 sensor cause this car not to start

i doubt that a faulty O2 sensor prevents the car from starting... it will affect how the engine runs but not starts... do you have CEL??

the EGR valve can do that... tf it is stuck wide open... i wonce pushed my EGR diaphragm while the engine was running and nearly at 3/4 of its travel distance the engine stalled... make sure that your EGR's diaphragm is not stuck open.

MMamdouh