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Geo Metro Engine Questions



  • blexodusblexodus Posts: 1
    We had the head rebuilt last year. This year we had the engine completely rebuilt because the front seal was leaking. Now when we travel on the freeway about 50 miles an hour white smoke comes out of the tailpipe. Looked inside the air filter and it was covered in oil which is going into the carburator causing it to burn oil. I do not know why oil is blowing into the air filter and into the carburator.

    Can anyone offer any help. Did not have this problem before it was rebuilt.
  • zaken1zaken1 Posts: 556
    edited April 2010
    Small correction here; Geo Metros do not have a carburetor; what apparently looks like a carburetor to you is actually the fuel injection throttle body. All Metros have throttle body fuel injection.

    When the air filter becomes clogged with oil; it will mess up the way the motor runs, particularly at high speeds. So you'll need to replace the air filter element, in addition to fixing the cause of the oil loss, before the engine can be expected to run right. The oil is coming into the air filter housing through the breather hose from the valve cover. One of the most likely causes of oil from the breather entering the air filter housing is a clogged PCV valve. The PCV valve is located just below the air cleaner, underneath the "T" in the breather hose which runs from the valve cover to the base of the air cleaner. Oil vapor from the engine normally flows out of the breather hose, down through the PCV valve, and through the intake manifold into the engine. But when the PCV valve becomes plugged; oil vapor then passes upward through the "T" in the breather hose, and goes directly into the air filter housing (where the first thing it does is to coat the air filter with oil).

    So I would replace the PCV valve, and make sure the air passage below the valve is not plugged. I would also replace the air filter element, and I suggest replacing the spark plugs as well; since they will often become fouled from running with a clogged air filter.

    If the motor is mechanically sound; the air filter should not plug up with oil again after the above items are replaced. But if the engine has been damaged by improper break in, by using the wrong grade of oil, by overheating, by using the wrong spark plug type, or by incorrect ignition timing adjustment; there will then be excessive quantities of oil coming out of the breather; and this will plug up the air filter even when the PCV valve is not clogged. In such a situation; your rebuilt motor will either have to be replaced; or rebuilt again and maintained properly this time.

    If you respond to this post; please include the year, model, transmission type, and number of cylinders your Metro has (assuming it is a Geo Metro). Also please include the length of time and number of miles on the rebuilt engine, the brand and weight of oil that has been used in that motor; and how many miles were on the rebuilt motor when the first oil change was done. I can suggest more specific options after I learn whether the motor has been damaged or not.
  • zaken1zaken1 Posts: 556
    edited April 2010
    You can buy parts like rocker arms for your Metro from a Chevrolet dealer. But if the reason you think your car needs rocker arms is because they are making clicking noises; it is probably not coming from bad rocker arms. Instead, clicking noises in the Metro's valve gear usually come from bad hydraulic valve lifters. Many small cars do not use hydraulic valve lifters; but the Metro does. These lifters are very sensitive to dirt in the oil, and will stick and make noise if the oil has not been changed often enough, or if low quality or non detergent oil has been used.

    Although Rock Auto does not carry Metro rocker arms; they do carry hydraulic valve lifters. The part number for the 1995 1.3 motor is Beck Arnley # 0227001. Price is $11.82 each. Intake and exhaust lifters are the same. This is a part which is very risky to buy used; because they are so vulnerable to dirt, and also because they wear in to match the mating parts on the engine in which they are used. If you put used lifters in a Metro; they will probably cause trouble.
  • Hi,

    Why, if the engine overheated, could there be oil in air filter box?
    What actually happens?
    Because I have a 91 Geo Metro/1.0L/A/T/133,000 miles and I did have this over heat on me and there is oil in air filter box!

    Thank you for any help!

  • zendenzenden Posts: 62
    Most likly blown head gasket or scored cyl. walls.
  • zaken1zaken1 Posts: 556
    edited April 2010
    There is a vent hose for the crankcase vapor; which runs from the valve cover to a "T" fitting that connects between the PCV valve and the air cleaner housing. Under normal conditions, most of the oil vapor is drawn into the engine through the PCV valve. But there is also a minor amount of vapor which goes into the air filter housing. A motor which is in good mechanical condition will not generate enough oil vapor to clog the air filter; but over time, there will still be a visible amount of oil left in the air filter housing. As the engine's pistons, rings and cylinder walls become more worn, the quantity of combustion gasses which get past the pistons and enter the crankcase will increase; and thus the amount of oil deposited in the air filter housing will increase. One measure of the engine's mechanical condition is how often the air filter housing (and throttle body bore) needs to be cleaned of oil deposits. I would say that if the oil deposits need to be cleaned out more often than about every 3 months; the engine is excessively worn.

    But, if the PCV valve becomes plugged or restricted; the vapor which normally goes through the PCV valve will instead go into the air filter housing. And that can make it appear that the motor is bad; when it is not. So I would always remove, clean, and test or replace the PCV valve, before assuming that the engine is producing excessive oil vapor. If too much oil is put into the crankcase; the same thing can happen.

    When an engine overheats; it can cause detonation (violent combustion) which can damage the pistons, rings, cylinder walls, valves, and/or head gasket. The heat can also cause distortion of the precisely machined cylinder bores and the head sealing surface. If any of these parts are permanently damaged; it will often lead to excessive "blow by" of combustion gasses past the pistons and into the crankcase. And the large quantity of oil vapor produced under such conditions will quickly flood the air filter housing and clog the air filter; even when the PCV valve is working correctly.

    This is why it requires judgment to decide whether the presence of oil in the air filter housing is a sign of a problem; or not.
  • we replaced the bottom half of the engine, had a hard time timing it and now it seems like it is running to rich, flooding itself, it is a geo metro lsi 1991, help!
  • zendenzenden Posts: 62
    edited May 2010
    Often when rebuilding, people forget the importance of reconnecting the ground wires to the engine; I am speaking of the small wires that connect the ECM to the eng; it bolts on to the rear of the plentum below the throtle body; it is connected with a 10 MM bolt. Or it sounds like the timming is retarded. You said that you had trouble setting the timming; I assume that you meant the distributor, and not the belt! Also maybe the spark plug wires are in the wrong place; each one maybe inserted into the cap to far to the counterclockwise position; If this is what is wrong then the eng. would run but have no power at all, the eng would lope and idle low. Move each one to the next hole in the clockwise direction. and turn the Distributor clockwise all the way, as far as it will go. If the eng wont start but kicks back or backfiers out the intake, turn the distributor in small increments counterclockwise to retard. If it backfires out the exaust then it is to far retarded. If it backfires no mater where you set the dist. after changing the wires then put the wires back where they where, and look for the reason for the trouble. a potato in the exost or cloged cat will do the same thing as you discribed.
    Let me know what you find. Hope that somthing that I said will help
  • rus6rus6 Posts: 1
    i have a chv metro 1998 1.3L that i am replacing the timing belt i have a repare book but it dos not show the timing marks on the cam shaft or the crank shaft when replacing the timing belt? HELP?
  • torakkitorakki Posts: 7
    I just rebuilt the engine on my 2000 Chevy Metro (valve job, pistons, rings, bearings) and when I finished putting it together and started it (started instantly). The idle is about at freeway speeds. Throttle butterfly is all the way closed. It runs smoother then ever, just way to fast. Before the rebuild, it idled fine, other then rough from a cracked and some burnt valves. One time, after letting rev for about 5 seconds, it started to slow then went slow and fast with a 1 or 2 second cycle. I've been turning it off after 4 or 5 seconds since I have brand new everything inside and wish to run it slow for a while. Any thoughts on what it could be? Air flow sensor on intake, crank sensor??
    Thanks in advance.....
  • zaken1zaken1 Posts: 556
    There is no air flow sensor on this motor. But if you did not connect all the idle air control valve hoses to the right places; there could be a massive vacuum leak into the intake manifold; which is what this sounds like to me. An EGR valve that stuck open or is being actuated at idle could also do this. Try disconnecting and plugging the vacuum hose to the EGR valve. If the throttle return spring has not been connected, this could do it, too. So could a PCV valve which was not in place, or a power brake booster vacuum hose which was left off.

    If the distributor was timed too far advanced, this could also do it. And if someone had broken the seal on the throttle stop screw and used it to speed up the idle when the valves were bad, that screw will now have to be turned back to the correct position (which is about 1/4 turn open from a completely closed throttle butterfly.)
  • torakkitorakki Posts: 7
    Thank you for the response. You hit it on the head. After checking all the vacum lines and hose connections, I couldn't find it but was sure it was a vacum leak. Then I saw one of the fuel injector wasn't seated right and air could get past it into the head. Loosened the fuel rail, repositioned all the injectors, re tighten the rail and, went to start it. It runs fantastic!!
    Thanks again for your help......
  • zendenzenden Posts: 62
    The crankshaft woodruff key will be at 12:00 ; this will make the lower marks line up.
    The camshaft has a pin sticking out, it will be at 6:00; then put the cam sprocket on, it has two slots coming out from the center hole; when correct the slots will be pointing toward 1:00 and 6:00 - ( NOT at 6:00 and 11:00) . Now the upper sprockets timing mark will line up and the lower mark will line up; both will point upwards. This is all you will need to know if you do it as I wrote. This info is correct for a 98 GEO Metro 1.3
  • trmechantrmechan Posts: 5
    I recently picked up a metro with the head off for a blown head gasket. I had the head checked and repaired and I installed it. Now the only way I can get the car started is to remove the bolts from the dist. and advance the ign. timming beyond the slots in the dist. I know I have the cam timming correct.
  • zendenzenden Posts: 62
    On the distributer try moving each sparkplug wire to the next whole in the counterclockwise direction, then set the timming.
  • danieldltdanieldlt Posts: 2
    I rebuilt this 1.3 L Piston rings, Crank bearings Rob bearings, Honed cylinders, Head worked on by separate shop valve job new seals and guides. Originally 97K but exhaust was smoking blue and compression was down to avg. 120 psi so decided to rebuild. After rebuild engine acts like it wants to start first 4 or 5 revolutions then stops. Plugs continue to be fouled by oil and fuel, cleaned them over and over. Timing should be on, have fuel pressure and fire from plugs... Any help you can think of would be greatly appreciated. Please help. Thanks!!
  • zendenzenden Posts: 62
    edited May 2010
    Are you sure timming is correct first? The cam sprocket has 2 timming marksthat are 180 degrese apart. the correct way is!
    The crankshaft woodruff key will be at 12:00 ; this will make the lower marks line up.
    The camshaft has a pin sticking out, it will be at 6:00; then put the cam sprocket on, it has two slots coming out from the center hole; when correct the slots will be pointing toward 1:00 and 6:00 - ( NOT at 6:00 and 11:00) . Now the upper sprockets timing mark will line up and the lower mark will line up; both will point upwards.
  • danieldltdanieldlt Posts: 2
    zenden, Thank you very much for the correct alignment position on the cam gear. I did have it wrong and have corrected it as per your information. I dont know why but injectors 1 & 2 are net getting the go ahead from the ECM/ECU, 3 & 4 seem to be working fine. Checked the blades on the cam that pass by the Cam position sensor and the look identical, could the cam position sensor be bad? How would I check it and , when I have the sensor unplugged 1 & 2 seem to be spraying intermittently??? I don't know what to do. Fixed the timing issue and now have another setback... Thank you for your time.
  • zendenzenden Posts: 62
    Sounds like a common mistake; maybe you forgot to ground the ECM back to the eng? Make sure the ground wire coming out of the main harness is bolted back on to the engine! On that eng I am not sure where it is located, On the 3 cylinder it would be locater on the firewall side of the throttle body (down low) it is bolted to it with a 10 mm bolt; on the 1.3 I am not sure! Hope this helps!
  • 3door3door Posts: 2
    Car is hatchback with 5spd manual and air, had it since new, now has 95,000 miles. In 2008 had it to repair shop for fast idle, 25mph. Blown ptc fuse caused by shorted EFE. EFE left unplugged. Still had a problem with fast idle, now up to 55mph in 5th gear without pressing on gas pedal. Computer replaced and ground wire added. Weather cooled down an Metro ran OK. Warm weather in 2009 above 60 degrees and car acted up, let it sit all summer. Drove it during winter (cooler months) no problem. Warm weather 2010, car is acting up again. Car may idle normal when started but once the engine starts racing it stays that way till the next morning, when it starts OK. It does still run at least 55MPH when the problem starts without touching the gas pedal. Thank goodness for a manual. Any ideas..
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