Only fires on 3 cylenders

[noel fowler]

Hi guys, first time to log on to this lifesaving web site.
My daughter has a1996 1.6 Ltr.SOHC Lanos which broke a timing belt about 18 months ago which I repaired but about 2 weeks ago the motor
started to act up.
The engine starts up as normal but after about 10 seconds number one cylender stops firing , and the car will not start again until it cools down and then number 1 shuts down again . I have changed the spark plugs, ignition coil complete with leads,put a timing tight on each lead - all fire as reqired ,swaped injectors from no 4 to no 1 but the problum still remains ,As I try to start the engine the crank turns over as normal at first but after 5 to 10 seconds the engine sound changes as if there was no compression.
Could you please tell me the location of the powertrane control module and the engine control module as there may be an eirthing problum with same.
My car in your hands
Regards Noel Fowler

[Rodd1s]

...
My daughter has a1996 1.6 Ltr.SOHC Lanos ...
...

are you sure? The daewoo lanos wasnt in production until 1997 and came with either a 1.3 sohc 8v, 1.5 sohc 8v or 1.6 dohc 16v.

as for the problem you're having... im not sure. never heard of one cylinder shutting down whilst the engine is running.

[noel fowler]

Thank you for your reply.You are correct about the year of manafacture it is 4/1999 .However all the other info is correct .I have just come back from my garage after checking the Y O M and started the engine and as orignal email it started ok but after ten seconds or so stoped firing on number one if I put my foot to the floor the revs will pick up but as it comes back to tick-over the engine just dies A check of the four exhaust manafold outlets shows number one luke warm and 2,3 & 4 quite hot the engine would not re-start and it cranked like there was no compression

[daewoomofo]

theres a good chance that you have bent valves from the timing belt breakage, unless you replaced the valves after. can you post a pic of your engine bay, im not saying that im a daewoo expert but im not sure that ive ever heard of a 1999 1.6 sohc lanos. where at in the world are you from?

[Trey05Woo]

Sounds like your suffering from a mechanical problem my friend. Either off timing, bent valves not seating in the guides correctly, or damged piston rings.

To answer your question the computer is located under the passenger seat, but I doubt that will be your problem.

Do a compression test this will guide you in the right direction.

[noel fowler]

Hi Daewoomofo.
When the tining belt tensioner bolt snaped 9 mths ago I had the head re-faced new valves, guides,springs & cam followers (rockers) cylender head bolts Gasket ect . I am sure of the Y O M . I have been living in Perth in Western Australia for the past 25 years . I was born in Dublin Ireland .


Hi Tray05 woo.
will try a compression test

Thanks for your help
Noel

[Trey05Woo]

No problem just post the readings and take it from there. Cant tell you what your problem is unless you have concrete information.

And Daewoomofo there is a 1.6l SOHC engine. Gen 1 D-Tec engines. Never made it to the states however... Its very common in Australia. No idea what models however, because I really don't follow Woos outside the US. But I vividly recall seeing a Cielo which was a 1.6l SOHC from my time at the dealers which sat for months as parts had to be imported from overseas.

[daewoomofo]

ok, well i stand corrected, proof that you can never know enough. ok so we know the head is 100% good, was installed good. (props given to you for doing it right!) how did the pistons look when the head was removed? how about the cylinder walls. only reason i was wondering bout your location is that it will kinda help others know more about your situation, like for instance now i know tha in AUS there was a 1.6 sohc lanos.

[daewoomofo]

actually trey the 1.6 sohc was in the pontiac lemans here in the states, i thought it was discontinued, but aparantly it was still available in AUS

[Trey05Woo]

Mofo think your correct. IIRC the Daewoo techs stated the engine was similar. Think block, but a key difference was Lemans used the wp as the actual physical tensioner, and the Aus Daewoo had a tensioner which was set by adjusting the wp like our cars...

Pending compression test readings interested in knowing what they are. For some reason I get the feeling valves are getting stuck in their guides and not seating properly.

[noel fowler]

Hi Deawoomofo & Trey05Woo,
Regarding piston damage when the timing belt broke:- Very slight surface markes to the piston crowns ( very lucky ) no need to polish or dress same .
This is where it gets interesting :- compression test starting with a cold engine 4 plugs removed Cyl 1 @ 165psi . cyl 2 @170 psi. cyl 3 @ 160 psi . cyl 4 @ 155 psi. Then I injected 3 squirts of oil into each cylender and started at cly 1 again ( rember I spoke about the engine turning over as if it had no compression ) The second reading on cyl 1 was 45 psi and nil ,zero, zilch , sweet f-all on the remaining 3 cylenders.
A further reading on one was nil .Next move bring out my compressor with a special fitting made to fit into the spark plug hole and with the two valves lobes on no 1 cyl at the piont of balance ( inlet and exhaust valves closed ) I blew compressed air into the plug hole and it came out through the inlet manafold and with the help of my wife I checked the exhaust tail pipe and compressed air could be heard at the pipe.
The same results for the remaining 3 cylenders .
Conclusion:- too much oil preasurs feeding the hydraulic lifters , WHY ? could be the oil preasure relief screw , spring or how ever oil is controled feeding the valve and rocker system. I have sourced a oil pr. gauge Ijust need to find the oil pr. sender switch and make the connection . I think 70 or 80 psi on the oil pr. gauge would be about correct ? So guys what is your opinion on the above?
Regards Noel.

[Trey05Woo]

Nope your valves are not seating properly my friend. With the engine turned off there is ZERO (0) oil pressure, and while cranking oil presure would be 8-10 psi tops. Your problem is mechanical when the valves return to their seats they are not seating properly. I don't mean to call out the machine shop but my guess is either the valve guides were damaged when they were getting installed or a poor quality valve or guide was used, or maybe even the valve springs were damaged. I would bet my bank accout you would experience a compression leak into the exhaust. This is because the exhaust valves/guides suffer the most due to the excessive temperatures they are exposed to. A poor quality valve or guide can warp when exposed to these temps.

Unfortunately, due to the engine design you cant get a clear view of the valve springs in action. Your only real alternative is to remove the head and source the root of the problem (valves, guides, and springs)

[daewoomofo]

yeah sounds like a valve problem like trey said. bummer cause you just did all that work to it to avoid this

[Trey05Woo]

better go back to that machine shop and throw down the house! I would especially if it was a customer's car the head went in.

Did you buy all the parts and send them with the head to the shop or did they source all the parts?

Back in 04 when I started to take in Daewoos on extended warranty, I sourced some valves from ebay. I installed them and about 2 months later the car came back no start condition and the exhaust valves looked like they had been grilled at a tailgate and the man incharge of the grill was too many beers in lol. Afterwards I sourced daewoous.com never had a problem again.

[noel fowler]

Hi Guys
Going on the theory that the oil preasure was too high and over preasureising the hydraulic lifters I drained the engine oil and replaced it with the lowest voscosity oil that i could buy which was W10/30 .I dont know what the old oil was but it took double the time to flow through a home made voscosity gauge ( a plastic cup with a 1/4 " Dia. hole drilled in the bottom with 2 inches of 1/4" Dia. tube stuck up into it for 1/2 an inch and time how long it takes to empty the cup of oil from a mark on the top lip to when the flow breaks )
AT THIS STAGE THE ENGINE IS RUNNING FINE
ONCE AGAIN THANK YOU ALL FOR YOUR HELP WITH THIS PROBLUM
REGARDS
NOEL.