Hosing off engine bay

The car is a 2001 Accent with 123,000km but the plugs and wires were replaced 2 years ago. I remove the leads at the coil side and they seem dry, the engine side is under a cover.

The car is running just slightly better after drying all night. It idles rough and the engine knocks at low rpm when I am on the road. The exhaust dropped black carbon on my floor this morning. The plastic piece (spoiler thing) in front of the cat? has melted but I cannot be sure that this is recent. I will get it in to service next week.

Funny thing is I had no problems and just wanted to clean my car.

It sounds like you ingested some water into the engine. This is pretty hard to do, but if the engine is making a mechanical knocking sound, it is possible that you ingested enough water to get a hydraulic lock in a cylinder when you first started it and bent a rod, cracked a piston, or cracked or chipped a valve. Again, this is really hard to do with modern intake systems, but it isn't impossible if you get water hard enough into the intake system. Good luck at the garage.

There's an old saying about not fixing things that aren't broken. Washing an engine certainly can be done without harm, but done wrong there is the potential for great harm to the engine. It is just like folks that speed into water a foot deep and wonder why they kill their engine.

Matt

I doubt that the engine took on water because I did not use that much to clean. I was careful to clean around the engine bay only and not the engine. If anything I should have left it to dry instead of driving it right away with the CEL blinking. Live and learn.

The weird part is that you say the engine is making a knocking sound. That isn't typical of an electrical problem. And the only way I know of for water to cause an engine to make a knocking sound is to get a hydraulic lock in a cylinder and bend or crack some metal. Maybe others here can think of another way that a little water could cause a knocking sound, but I can't.

The rough idle could easily be a wet ignition component or sensor, but the knocking sound is of much more concern.

Let us know what you find at the garage next week.

Matt

Maybe I am not describing the problem correctly. It is definitely a rough idle but no "knock" sound when it is parked. Only when I am driving at low rpm, it feels like the engine is near stalled then I hear the "knock", may not be the engine but somewhere else. I play with the throttle to keep the car moving.

The car is drivable but I do not want anymore problems. Wonder if I should get it towed.

If the engine is nearly stalling all of the time, then maybe the knocking isn't a mechanical failure. No way to tell without hearing it first-hand. If you are sure you didn't get a lot of water into the intake, then I don't see how you could have done any serious damage to your engine.

It doesn't seem like driving it should cause any further damage, although if it is misfiring badly it is possible to dump enough raw gas into the exhaust system to burn up the catalytic converter and that is a pretty expensive repair.

Matt

I afraid that is what has happened. I have decided not to replace the catalytic converter if it is needed. Is it an option to fix just the misfiring and continue driving the car with a damaged catalytic converter?

Thanks for your time.

Accent, you can always try a test pipe on the cat ( snicker ), I know in the older days we used to have a pipe made to replace the cat.... Im not so sure its a good idea these days the way technology has changed but if you can get a muffler shop to make you one JUST TO TEST and see if the cat is bad it may be worth the $25 - $30 to try it.

Tunez

It depends on the damage. Burning raw gas often melts part of the converter substrate and this will increase back pressure, sometimes dramatically. Your car will NOT run well if that is the case. Also, and I'm not familiar with the Accent to be sure, many cars now have both an upstream and downstream oxygen sensor. If the catcon isn't working properly, this will light the check engine light. In many states now this will prevent your car from passing the annual inspection.

And that is to say nothing of the pollution you are spewing into the environment.

It will be better to get it fixed correctly, even if that does require a new catcon.

Matt

re: drying engine

if something gets tooo damp and doesn't start or run up to snuff, then what would WD-40 hurt (which parts shouldn't be sprayed with wd-40)?

it's considered more of a "dryer" than lubricant from what i've previously ascertained in these n.g.s, tho i sort of use it for everything along with duct tape

Based on the fact that he's getting sooty exhaust and it appears that the catalytic converter has overheated, I'd say that's definitely NOT the case. It would be almost impossible to do, anyway. It's far more likely that he just has a bad misfire due to an electrical problem. That would explain both the overheated cat and the soot.

The knocking is likely caused by cross-firing cylinders.

What brand of wires and plugs were installed? Some aftermarket wires are junk right out of the box.

Remove the cover from the engine and check underneath. You may find the source of the electrical problems there.

I overheated my cat converter just the way you apparently did. Aside from smoke, flame, and consternation, it didn't hurt anything. The cat lasted another 3 or 4 years until I sold the car.

The secret to drying the engine out is to run the engine al little, and dry it a lot. Keep the hood open and in full sun and wind if you can.

The car has been maintained at a Hyundai dealership. I assume that they will use OEM parts but I really have no clue.

This time the car went to an independent garage. The scan and scope test indicates the a complete tune up is needed including wires and plugs. Any damage to the catco will have to be assessed after the tuneup.

I'm sure that's the case.

Did you check it out yourself, first?

Make sure the garage saves the old parts. If the problem turns out to be something else, the old parts will make good spares. This is also work you should consider doing yourself, as it's easy and at least you know what was done and how.

There's really nothing more to a "tune-up" unless you want to replace the air filter, too.

Hopefully, there won't be any residual problems.

I did not bother checking it out first and decided to leave it to the professionals. The tuneup must be more to it because it comes with a high cost. The OEM air filter is brand new. I will leave the old parts to the garage.

What other items should be in a complete $300 tune up with $100 scope and scan test?

1. wires and plugs
2. oil and filter (2000km earlier than scheduled)
3. valve timing

That may have been a mistake.

OK.

Why? You paid for them, didn't you? If they're relatively new, they'll make good spares.

There is no way you should be spending $300 on a tune up. Wires and plugs should be under $100. If you don't need an oil change for another

2K miles, don't do it. There is no adjustment for valve timing. $100 for "scope and scan" is ridiculous, too. It sounds like you're getting screwed. Just because someone gets paid for working on cars, it doesn't make them true "professionals".

I have a feeling that I am not getting the best value for my money because the car was running fine before my ordeal. I will see what is on the itemized bill when I pick up my car. Would be nice if I also got a coolant flush, transmission flush and new fuel filter.

It is too bad that I did not follow your good advice and check the plugs and wires. Next time the car is misfiring, it will be the first things to be checked.