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The title is pretty self-explanatory. I have a 2003 Mazda Protege5. It's a 2.0L 4-cylinder with a 5-speed manual. Exciting, I know. I don't have cause to drive all that far or often, as I'm currently an unemployed college student. (Currently sitting just shy of 89k miles.) Campus is about 12 miles away, and I drive in anywhere from 3-5 times a week (or not at all, now that summer is in swing). I recently interviewed for a seasonal job, and noticed a rough idle. It got progressively worse, and when I checked out my engine, I found oil in the #2 cylinder. I don't see any apparent leaks from the head gasket. Am I going to have to replace some piston rings? Is this something I can reasonably do myself, or am I better off handing it over to my mechanic? (To help answer that, I'm perfectly capable with minor work: alternator replacements and the like, but I've never dug this deep into my engine.) I'd kind of like to try it myself, but I'm a little intimidated. I don't really have the money to fix a royal screwup, but I also don't really have the money to give my mechanic. I guess it's either pay to fix this problem, or pay a lot more to fix whatever damage I wind up causing?
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Jun 6, 2015 18:50
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| # ? May 6, 2024 11:05 |
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the amber trap posted:The title is pretty self-explanatory. Is there wet oil actually in the cylinder? Was there any oil in the spark plug well? Often the cam covers leak, oil gets into the spark plug well and causes a misfire as it increases the resistance between plug and lead/coil pack.
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Jun 6, 2015 19:18
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I looked down the well without the plug in place, and I definitely saw oil on the cylinder head. I guess it could have fallen down from the well if that's where it was, but the working end of the plug seemed really wet.
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Jun 6, 2015 19:30
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Mooseykins posted:Is there wet oil actually in the cylinder? Was there any oil in the spark plug well? Often the cam covers leak, oil gets into the spark plug well and causes a misfire as it increases the resistance between plug and lead/coil pack. If its this, its an easy fix. Has there been any major engine work done by a previous owner, specifically the head gasket? If so, the valve seats are probably bad and oil is leaking from the top of the valve into the cylinder bore. This causes a big cloud of blue white smoke in the morning. This happened to me but I kept driving it for another 20k miles before I sold it. OR... Has there been a huge jolt while the engine in under load, like it felt as if you had crashed into something and then the car started hesitating and idling rough. If so, you are very lucky and had a piece of the notorious VTCS system pass through your engine and come out the other side. (happened to a friend of mine). You engine is hosed but you can at least limp around for a couple of thousand miles like that if your broke. well never mind its the valve cover
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Jun 6, 2015 19:40
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I've owned the vehicle for the last 30k miles or so. I assume that means anything the previous owner did would have shown up by now. No huge jolt. I'll try replacing the valve cover gasket, but I swear I didn't see any obvious leaks from there into the spark plug well. I guess I'll know for sure once I get the cover off. edit: Just realized that I hadn't noticed any blue smoke or other indicators of oil in the cylinder at all, so it probably wasn't in the cylinder. Now that I've dumped some in there, can I just run the engine to burn it out, or is it better to try and clean it when I'm replacing the gasket? If so, how would I clean it? the amber trap fucked around with this message at 19:47 on Jun 6, 2015 |
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Jun 6, 2015 19:44
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Eh, I'd just change the plug and see if it reoccurs. Plugs are cheap, if you have no money you might be able to get away with replacing the bad one every now and again for a few bucks.
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Jun 6, 2015 21:14
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I was planning on changing the plug anyway. Are you suggesting to not worry about the gasket for now? What about the leak?
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Jun 6, 2015 22:20
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If you're really concerned about the rings, get a compression tester. Test each cylinder twice, once dry and once after pouring a small quantity of oil in the cylinder. If compression is bad but gets better, it's probably rings. If it's bad and doesn't improve, either head gasket (you can rent a chemical vapor tester to check for exhaust fumes in the coolant, but bear in mind an oil channel could leak into the cylinder without coolant leaking) or a valve sealing issue (you'd need a compressor and a leakdown tester for that one). If compression's good all around, it's most likely either valve stem seals or the valve cover gasket, although if the upper ends of the plugs (where the boot attaches) aren't wet with oil it's probably not that. Is there any oil leaking externally? If there is, you can wash the engine down and check over the next few weeks for fresh oil to see exactly where it's coming from.
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Jun 7, 2015 00:24
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Yeah I'd get a compression test on it before I started worrying about anything. Even then, as long as it's not ridiculously low just change the plug now and then and just drive the drat thing if you're a poor college student. And do the valve cover gasket just to be sure, it's cheap and easy.
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Jun 7, 2015 02:34
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I wasn't really concerned with the rings, but because I didn't see any obvious leaks in the spark plug well and because I completely forgot that gravity makes liquids move down, I was trying to figure out why there would apparently be oil in the cylinder. Thankfully, you folks were good enough to jog my brain into some sort of function, and I feel a little better about the issue now. Once I rustle up some spare change, I'll replace the gasket and plugs, and hope that things should be set. For now, I can take the train to work and suck it up until I get paid. Thanks for your help. I'll update if that seems to fix everything. Or if not, I guess.
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Jun 7, 2015 05:11
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| # ? May 6, 2024 11:05 |
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the amber trap posted:Now that I've dumped some in there, can I just run the engine to burn it out, or is it better to try and clean it when I'm replacing the gasket? If so, how would I clean it? As long as it wasn't a massive amount of oil (i.e. the spark plug well wasn't full to the brim), just put new plugs in and drive it. Worst case, you get a little bit of blue smoke for a couple of minutes. And it wasn't full to the brim; if it was, you would have had a misfire on that cylinder for quite awhile. Keep an eye on the oil level. If it's not going down considerably between oil changes, then it's just the spark plug tube seals on your valve cover. With a 2003, I'd be shocked if it WASN'T leaking oil from multiple gaskets - especially with how little it gets driven.
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Jun 7, 2015 05:39
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