Calling Dr. House - I need a diagnosis

Hi all,

Been a while since I posted. I was going to post my exploits pulling a piston with a broken skirt from my 1.0, but Doc Bill did such a good job I didn't see any reason to put more of the same up there. Suffice to say, in 3 days of about 12 hours a day, I managed to get my poor little car up and running again. Bill, that feeling of turning the engine over after all that and having it sound "normal" is second to none, eh?

Well, it's been a year and about 40K more miles (99.5% highway) and I've got a problem that I *think* I have figured out, but would like a second, third, fourth, etc. opinion to make sure I'm not :screwy:.

Here's the background on the car: When I got it, it had been running without a thermostat. The first owner added a 3rd party a/c system, and had disconnected the heater core from the coolant lines and removed the thermostat. I think this is b/c when I found everything disconnected and reconnected it, the a/c puts a huge heat load on the engine. If the air's on and I'm on the highway, it runs just below the red on the temp gauge unless I kill the compressor temporarily. I'm tempted to get an underdrive pulley just to reduce the stress this thing puts on my engine. I lose about 4-5 mpg (42 to 36 on average) if it runs for an entire tank of gas. Other things I've done: As mentioned above, last year I replaced a cracked piston with a new one, re-ringed all 3 pistons and replaced the rod bearings. It's been running great ever since until very recently. I had to have the water pump replaced recently, and it was ok after that for a little while. It has no oil leaks, except a very slow drip where I accidentally overtightened an oil pan bolt and put a small split in the cork gasket. I tried sealing it with RTV but it still drips a little. No noticable drop in oil level from it though.

Within the last couple weeks, it developed a tic. Or rather, a tick, as in ticking sound. It would go away after running the car for a while, so I figured noisy lifter, and just to be sure I dropped the oil pan and found the pistons were fine. Shortly after that, I noticed a rough idle and a little weakness at low RPMs intermittently. I have the timing set at 10 degrees advance with no pinging/detonation (I credit the E3 spark plugs for the extra degree or two). I also just cleaned out the EGR system when I got a 51 code from Mr. ECM. And I replaced the fuel filter.

Anyway, skip ahead a week to now: When it's cold, at idle under load (i.e. a/c on and just starting in the morning), the engine runs rough for a few seconds then stalls. At idle w/no load, it idles a bit slowly and occasionally cycles up just a little bit, but never stalls. Under low throttle it runs a bit rough, missing or hesitating intermittently, especially under load, and has low power. At high throttle, everything evens out and I get most of the power back that seems missing, unless I undershift and lug the engine :smokin:. It's a bit weak getting up the larger mountains, but not so bad I have to go lower than 4th gear (it used to make the same trip in 5th the entire way though). It cruises smoothly at mid-high rpms in any gear, even with the a/c on. After it's been running a while on the highway, it will smooth out for the most part and idle normally when I come to a stop. It still has a little trouble with the a/c on and idling at that point, but it hasn't stalled if I leave the compressor on after the trip and come to stop.

I initially thought vacuum leak, but I've checked everything and other than fixing the tube connecting the silencer to the air intake, the other tubes and base gasket seem fine. Being a postdoc, aka indentured servant, I haven't been able to get a compression gauge yet, but that's on tap for tomorrow.

So.....I think I know what the problem probably is, but I'm not positive and don't want to make any investments without exploring other possibilities. I don't want to contaminate the answers with mine yet :grinno:, I want anyone else's :2cents: first. So whoever wants to contribute a guess, educated or not, I'd love to hear from you. I'd make more of a contribution in terms of tips and tricks, but DOCTORBILL's already spilled all of my beans for me. :iceslolan

PS It's a standard G10 engine/manual tranny aside from the a/c, no other mods.

When I bought my used '93 3 cyl, the previous owner had removed the A/C
belt and I left it that way. I've never had the A/C running.

I open the windows and let Mother Nature cool me down. 59 hp running an
A/C and the automobile too seems like 'cruel and unusual punishment' to me.

And yes, when the engine ran like a sewing machine motor after I reassembled everything,
I couldn't believe it! It has 12,000 miles on the rebuild now and the oil won't darken
after 3,000 miles! More power than I can believe!

That little 3 cyliinder Suzuki Engine is a marvelous piece of engineering!
It's like the Jeep in line six cylinder, 4 liter engine - just keeps on going....

"I also just cleaned out the EGR system when I got a 51 code from Mr. ECM."

My thoughts probably have nothing to do with your problems....but

If yours was as filty as mine was, I'm wondering if you still have CHUNKS of
carbon left flopping about in the TB. I used my Shop Vac with a copper tube
taped to the hose to suck the carbon out after reaming with the expanded
spring tool I made (in my thread).

Also, if your vehicle is old (you don't give the year), how do you know the Fuel
Pump is delivering properly.

Crvett69 suggested that I disconnect the delivery hose and measure the fuel
delivery rate on mine. Man, it pumps really fast!

I also bypassed the fuel filter back by the tank (replaced the filter with rubber
hose) and put the filter up front just out of the fire wall - easy to replace
now !

I'll be interested in learning what your solution(s) is/are....

DoctorBill

PS - Still farting with the Cruise Control....been too hot to work on it.

Do get some compression readings. The fact that you are running this engine so hot concerns me - they're small, all aluminum, and with the "floating" cylinder style block DO NOT respond well to overheating. Now that I got that off my chest. I agree with you suspecting lifters - although I have never had to replace any (yet) with now 26 and counting metros to look after and 6 G10 rebuilds. Perhaps you have some bad lifters, maybe some debris found it's way into the channel which sends oil from the pump to the lifter vally to pump up the lifters causing them to "deflate" on cold starts. Your oil may be too thick (what viscosity are you using?). Rent/buy a gauge and measure you're oil pressure, it could be low at idle, or low overall - agian, starving the lifters.

You may also have a bad ECT sensor, or blocked coolant passages leading to it (them - depending on year).

Check to see if maybe you have an exhaust restriciton. It may subside after the system heats up and expands, generally these come on quite strong - disabling these metros in fairly short order, but still something to consider? If push comes to shove, disconnect the manifold from the head and see if it idles easier. Do this very briefly, as the heat will melt 02s wires and such - ask me how I know =)

*EDIT - Doctor Bill, How are you sir?*

-MechanicMatt

91Caprice9c1.....

"*EDIT - Doctor Bill, How are you sir?*"

Doing fine - enjoying my rebuilt '93 !

Trying to figure out why my Audiovox Cruise Control refuses to work while
everyone else's works immediately on installation.

They replaced EVERYTHING - still doesn't work.

Checked EVERYTHING - still won't work.

I am cursed.....

DoctorBill

PS - decided I will not settle for an Automatic for my daughter - has to be manual transmission.

Syndrome Zed,
One low-cost and simple item, but important - the PCV valve. Check and/or replace this item. Replaced mine for just a couple of bucks. The original one was completely clogged, and not allowing gases to escape from the top of the cylinder head. Not good. This probably won't fix your problem, but it may have been a contributing factor if it is clogged.

I had recently replaced the cat and muffler on my '05 1.0L. It's like a completely different car now. Amazing. The catalytic converter must have been very clogged. The 2000-2001 manual talks about removing the 1st O2 sensor temporarily and inserting a exhaust gas pressure gauge. Check at idle and at 2500 rpm, both with engine warmed up. Differential positive pressure should not exceed 1.25 psi in both cases, otherwise there is a blockage of some kind. (Of course, you have to find yourself an exhaust gas pressure gauge.) This is for the 1.3L. Couldn't find similar description for the 1.0L. (Maybe '00 and '01 didn't come with the 1.0L.)

^^ good advice about the PCV - if you like engines that last anyhow.

-MechanicMatt

Well, the results are in - finally had the time to get a compression test gauge and do the test. That poor engine failed about as badly as Dubya's "exit strategy".:cya:

The numbers, in order C1-3, Dry/Wet:

110/110
210/240
60/80

In other words, I'm running on about 2 full cylinders total. :crying:

Based on the quick and dirty interpretation of the data over at Teamswift, I'm looking at a "leaky" head gasket and at least one burned valve. Not to mention the ticking is probably a bad lifter - unless the burnt valve also happens to have burned so badly that the lifter simply isn't being pushed by the exhaust gasses anymore (if I have that right - I may have it backwards).

Needless to say, I went to Ecology Auto parts and pulled a Cylinder head from a 90 (my car's a 91, DOC, sorry I forgot to mention that) that had a rather nicely intact engine. It looks ok, but I bought new exhaust valves, etc. anyway. Took the lifters and camshaft with the head, just in case there is a bad lifter needing replacement. I figure I'll keep the camshaft and maybe have 3Tech grind it to better specs later on down the road. I'm not worried about the rings - no oil at all being burned and I just replaced them a year ago. I know, I should have done the valves when I did the rings, but I'm lucky when I have :2cents: to rub together.

sas95 - I agree about the PCV valve. When it first started grumbling at idle, I pulled the old one. It was clogged with oil, as you suspected, and I replaced it, cleaned out the T-tube and header on the valve cover, and put it all together again. I've checked once since then and the valve's clear still. But it could certainly have contributed.

91Caprice9c1 - Do you think the lifter's just being noisy b/c the valve it's supposed to lift is completely trashed? I know you can push on them to test them - is that the main way of doing it? It was noisy when I had 5W-30 in the engine, so I briefly tried some 20W-50, but it didn't help (gave it a week, about a thousand miles), so I replaced it with the 5/30 again. The coolant passages don't seem to be blocked - I've done a radiator flush and was able to push water easily through all the tubes, but that damned cat could be blocked. It could be that that's where the extra pressure is coming from to force the oil into the PCV header/valve. Can I use the compression gauge to test the exhaust pressure? I'm tempted to drill a hole in the header connecting the exhaust tube to the cat to just to see if it helps. I know the top half of the engine's shot, but if the cat's blocked and that's what caused the valves to go South, I don't want to repeat the damage. Anyway, if I drilled a hole in the exhaust at the cat, could I insert the comp gauge in the hole and measure the pressure there? Or could I use it like Sas95 explained, plugged into the oxy sensor hole?

DOCTORBILL - Sorry I can't help with your Cruise Control - my only advice would be to uninstall it and reinstall it completely, the same advice I'd give a Mac user or someone whose PC is totally fragged. And strangely, it seemed to work with my old VCR too. :wtf: If I ever get one installed (it'd be nice considering my commute right now) and it works, I'll send you mine. You've sent away for a new unit from Audiovox, right? Or sent yours to them?

I usually can skip the A/C, but the last couple weeks' heat wave has been a bear - upper 90's where I work every afternoon, so the trip home I've needed it. And of course, when I went to pull the cylinder head from the other car, it was 108F and no shade. Rialto/Bloomington, CA = :devil:, and Me = :newburn:. So I've been manually cycling the thing to keep the coolant temp reading at no higher than 2/3rds of the way up to the redline and still trying to keep myself from heatstroke, waiting impatiently for the heatwave to break.

I have to agree about the engineering of these little engines. It amazes me every time I pull it apart and think about how each little part is timed together, how incredibly small the tolerances are (.05 mm??? :yikes: My microscopy equipment at work isn't even that tight), and how the thing can have such small tolerances, burn at 700+ degrees F, and still it can run for hundreds of thousands of miles of use. How Daimler and Benz ever came up with these things is beyond me.

Well, if I can replace a piston and rings in 3 days, I can replace the head in 2 afternoons too. Stay tuned....:runaround: