Welcome Guest [Log In] [Register]
Posted ImageWelcome to the all new Geo Metro Forum. We hope you enjoy your visit.

You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features:

Join our community!




Username:   Password:
Add Reply
Mysterious Oil Burn Problem; Burns oil - unusual compression results
Topic Started: Jun 1 2010, 12:49 PM (1,503 Views)
c140flyer


Hi Folks,
I've had my '92 Metro now for over two months. I've had a lot of small problems which I've actually enjoyed the challenge of resolving (lots of wiring issues, window regulator probs, oil leaks, radiator leaks, etc.). The previous owner had done some "creative rewiring" and mentioned that he also had done a cylinder head job. :hmm

I was going through 1 1/2 quarts of oil every 400 miles. I had an oil leak that would leave puddles of oil everywhere I parked. It took me a while to figure out the problem. After replacing the distributer o-ring ring twice and valve cover gasket, the leak persisted. Finally I read where there was a gasket between the distributer housing and head that I found missing. Made a new gasket and the engine compartment was dry as a bone. I assumed that the oil usage problem was over. Not so! I'm still going through a quart every 500-600 miles. The engine I sold from the '96 never needed oil between changes.

When I bought the car, I'd performed a dry compression test . #1 - 185, #3 - 180, #2 - interesting. The first reading I took for #2 showed 120 after 5 seconds of cranking (with throttle open). I cranked again and got 175. The car ran great,so I figured that I messed up the first time.

As I said, the car runs great. I'm getting 53-55 MPG and it has lots of power. I thought it might have something to do with the PO using a head gasket with small oil return holes. I checked the PCV valve and it looked OK.

I redid the compression test dry and wet with the car at normal operating temperature.. #1- 180 dry/190 wet -good #3- 175 dry/185 wet -good #2 (drum roll)... bizzare results: 60 dry (first test), 90 dry (2nd test) 0 (as in zero) wet (first test) 90 wet (second test). I buttoned it up and drove it around the block and retested #2 again. I got 180 dry and 195 wet! :banghead

Not sure what to check next. I thought I might try a leakdown test. Someone at work thought I could have a bad lifter or a stiking valve. Not sure how that would affect oil burn rate.
Any suggestions? I'm almost hoping someone will find something obvious and make me look like an idiot!
Thanks,
Larry
Offline Profile Quote Post Goto Top
 
slander
Member Avatar
Tech Certified

If it's coming from that side of the car, is there still oil coming from the underside of the distributor? If not, yet it still coming from that side of the car, check your rear main seal.

EDIT: Forgot to add, if you're getting 50+ miles to the gallon, the car runs well with good horsepower, and you're getting funky readings like that, I would be skeptical of your pressure tester.
Edited by slander, Jun 1 2010, 12:58 PM.
Offline Profile Quote Post Goto Top
 
bennie442


A bad cam seal or crank seal will lose engine oil without getting your engine compartment messy. Look at the bottom of the timing cover. See any oil?
Offline Profile Quote Post Goto Top
 
c140flyer


I think you guys are right about the cam/crankshaft seal oil theory. I do have some oil there, but it doesn't drip like the other leak did. When I fixed that leak, it only reduced the consumption by a few ounces per tankful, but hopefully you're right. I'll pull the cover when time permits.

I think the compression problem is a separate issue. I think the gauge is OK, because the results of #1 and#3 are consistent. It's probably a stuck valve or lifter problem. From what I've seen of the PO's work, he probably screwed up the valve job :spaz .
Thanks,
Larry
Offline Profile Quote Post Goto Top
 
mcmancuso
Member Avatar


You might have a bad oil ring that's letting oil into the cylinder? don't know if this would have a negative effect on compression but it would let it burn oil.
Offline Profile Quote Post Goto Top
 
nerys
Member Avatar
Grr

Also check your threads on that spark plug hole. Might eliminate compression as the problem IE if its intermittently not SEALING properly you would get those wonky readings.
Offline Profile Quote Post Goto Top
 
crankcase


Stuck rings mucked up with lacquer might be causing those types of readings and symptoms. I've heard of people adding lacquer thinner to the cylinder and working the crank by hand (repeat a few times) to free things up. After doing this the oil & filter must be changed.
Offline Profile Quote Post Goto Top
 
mwebb
Member Avatar
FOG

..."I redid the compression test dry and wet with the car at normal operating temperature.. #1- 180 dry/190 wet -good #3- 175 dry/185 wet -good #2 (drum roll)... bizzare results: 60 dry (first test), 90 dry (2nd test) 0 (as in zero) wet (first test) 90 wet (second test). I buttoned it up and drove it around the block and retested #2 again. I got 180 dry and 195 wet! :banghead "...


if you connect a vacuum gauge
Teed into the MAP sensor vacuum line BEFore the restriction orifice .
intake vacuum MUST be around 20" at hot idle with ZERO flutter
if you have intermittent flutter , you have a valve problem .

also
using the wrong oil will cause this
the oil in the engine MUST NOT be 10w40 or 20w50 ....

for best results and longest engine life the best oil
is
European specification
ACEA A3 B3 - B4 5w30 synthetic oil
it is also the Cheapest as in most frugal to use
Offline Profile Quote Post Goto Top
 
nerys
Member Avatar
Grr

"ACEA A3 B3 - B4 5w30 synthetic oil "

how about just telling us what brands of oil in the US meet this specification.

I HAVE NEVER ONCE seen a label that said "ACEA A3 B3 - B4 5w30 synthetic oil "

its always variations and inclusions etc.. etc.. XXX and all previous etc..

give us a brand and model or oil that is ACEA A3 B3 - B4 5w30 synthetic oil
Offline Profile Quote Post Goto Top
 
mcmancuso
Member Avatar


:) I agree give me a brand :) I too have never seen those specs on a bottle. the mobil 1 I buy says: ILSAC GF-4 ACEA A1/B1, A5/B5 API SM, SL/CF GM 4718M GM 6094M Honda HTO-06
Offline Profile Quote Post Goto Top
 
c140flyer


You mean I can't use 85W90 gear oil in the engine? :O
Just kidding. I use Mobil One semi-synthetic 5W-30. I used it in all my cars for the last 2-3 years with no problems.
I'll take a look at vacuum. I just found a neat compound gauge that should work.
I also have a differential leakdown tester that I use on aircraft that needs to be adapted to 14mm sparkplug threads (a/c are mostly 18mm). That should tell me the source of the leak plus give me another data point.
Thanks,
Larry
Offline Profile Quote Post Goto Top
 
Coche Blanco
Member Avatar
Troll Certified

c140flyer
Jun 2 2010, 11:47 AM
You mean I can't use 85W90 gear oil in the engine? :O
Just kidding. I use Mobil One semi-synthetic 5W-30. I used it in all my cars for the last 2-3 years with no problems.
I'll take a look at vacuum. I just found a neat compound gauge that should work.
I also have a differential leakdown tester that I use on aircraft that needs to be adapted to 14mm sparkplug threads (a/c are mostly 18mm). That should tell me the source of the leak plus give me another data point.
Thanks,
Larry
Gear oil is too thin. I use bearing grease.
Offline Profile Quote Post Goto Top
 
mcmancuso
Member Avatar


LOL! Man just step up and run paraffin (oh and make sure you have a block heater on it when its not running) ;) That'll stop the oil burning and leaks :D :banana
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
ZetaBoards - Free Forum Hosting
ZetaBoards gives you all the tools to create a successful discussion community.
Learn More · Sign-up Now
« Previous Topic · Engine Tech & Diagnostics · Next Topic »
Add Reply