Oil and Water Not Supposed to Mix!
May 6, 2011 6:11 PM   Subscribe

Diagnosing head gasket problem - do I really have to spend $1K here?

2004 Hyundai Elantra, 73K miles. I went to a Korean mechanic just to change the oil, and he lifted the oil cap and saw some grey deposits on the inside of the cap. He says it's a mixture of oil and water, indicating that there's a head gasket problem. Lifting the entire gasket assembly and sending it to a shop to retool, plus all the labor and stuff, is about $1K.

Now, the problem is that his English is very poor, so it's a bit of a hand sign issue, so I can't be sure of all he said, but that's about the gist of it.

He advised watching the temp gauge very carefully, topping off the radiator water, and if temps ever climb above safety, shut off the engine immediately and bring it in.

He also said, that based on his cap diagnosis, he's 99% sure it's a head gasket problem and I'll need to spend the $1K. I trust him completely as far as honesty goes, but I just don't know if he's right here, based just on the cap oil+water evidence.

My fear is that if they need to disassemble the engine and it's not clear that there is in fact a head gasket problem, then it amounts to a fishing expedition that fixes nothing. I don't even mind the $1K, but I simply don't feel confident that this in fact takes care of any real problem.

FWIW, I have never observed the temperature gauge go above the half-way mark, and have in fact been paying attention (this is a habit, based on having had a water pump fail on my Toyota once).

I don't feel like dragging this thing to various mechanics just yet, with all the time sink and diagnosis issues, so I turn to the hive mind first.

How accurate is a cap deposit of oil+water as a diagnostic of serious head gasket problems? Do I need to take action now, or can I just watch the temps until more clarity obtains - if the temp goes up, at least I know for sure there's an issue, and then I can go to a mechanic with a clear conscience... I just hate fishing expeditions. Is it advisable to do the following: clean off the deposit inside the cap, and then re-check in a month or so, to see if a new deposit of oil+water appears, at which point I'll have confirmation of a body buried somewhere. What's the next step, short of immediately throwing the car to the mechanic's mercy and accepting whatever comes?
posted by VikingSword to Technology (19 answers total)
As far as I know, there shouldn't be any way for oil and water to mix in the engine without some sort of 'breach' - either the gasket, or the head has warped (which may be where the 1K is coming from), or there's actually a crack in the block. I would imagine he's seen enough of this model suffer from warped heads that he 'knows' there's a problem. If you start seeing the temp go up, it may be too late. A month's worth of driving with water in the oil sounds bad to me too.

IANAM, just have had a warped head on an Isuzu and a blown gasket on an old Plymouth.
posted by pupdog at 6:21 PM on May 6, 2011

A failing head gasket is one thing that can cause this, but it's not the only thing. I'm not expert enough to enumerate all the reasons it might happen, but it's fairly normal for some engines, possibly depending on your driving habits. I think you're right to be skeptical.
posted by jon1270 at 6:33 PM on May 6, 2011

We had a mechanic tell us we had a gasket problem that was also going to cost in the range of a thousand, but then we got...oh, crap, what's the name of it? There's this goo you put into the radiator to seal off any leaks, and it's probably some horrible idea that will destroy the car, but we put it in there two years ago and we haven't overheated once since then.
posted by mittens at 6:36 PM on May 6, 2011 [1 favorite]

A bad head gasket, in and of itself, would not cause your engine to overheat. The loss of coolant would. Was there any sign of water in the oil on the dip stick? Having localized on just the cap is suspicious to me. I would monitor the coolant level and check the oil on the dip stick daily. If the coolant stays full and there is no sign of water in the oil (it will look like gun metal grey pudding) then I would not be concerned. If the coolant level goes down and/or the oil turns color, go directly to the mechanic and get the head gasket changed out, the head milled and a complete oil change. He should probably magnaflux the head and the cylinders as well just to eliminate the possibility of a cracked block or head.
posted by Old Geezer at 6:44 PM on May 6, 2011

A couple of things:
1) A head gasket, when all is said and done, is going to be much more than $1k. Why was that number mentioned?
2) What's your diving regimen like? Do you make a lot of short trips? That kind of driving can lead to condensation build-up on the top of the valve cover (where the oil cap is).
If it were me I would wait, keeping a close eye on the temp. gauge and coolant levels, and maybe looking for a new mechanic. If you're really worried, a "leak down test" (with another mechanic) will give you a definitive answer.
posted by Mr.Me at 7:00 PM on May 6, 2011

Is there oil in your radiator water? When the car is running, is there a smell of antifreeze in the exhaust?

Keep an eye on your coolant level and your oil. If your start getting water in your oil (grey sludge on your dipstick rather than just a little condensation around the oil cap) then yes, you have a problem and an head gasket is a likely cause. If you never see more than some residue around your oil cap, you might not want to panic just yet.
posted by Kid Charlemagne at 8:23 PM on May 6, 2011

Don't Hyundai's come with a 10 year/ 100,000 warranty?
posted by JohnE at 8:27 PM on May 6, 2011

Thanks, everybody, so far. I'm going to check on the suggestions wrt. oil, radiator etc. sometime tomorrow. Re: driving regimen, I don't use this car much, to be honest, usually doing short shopping trips on the weekends, a few miles, and like two very short trips mid-week (a couple of miles), that's it. But, also, 3-4 times a year, camping trips within California, each about 300-600 miles in toto. Yearly about 3K-5K miles for the past 3 years. Re: $1K, it was mentioned as a minimum, because of the disassembly, I'm not sure what the final cost would be. No smell of anti-freeze.
posted by VikingSword at 9:58 PM on May 6, 2011

A good mechanic will perform the correct test to establish this as the cause.

If there's a breach between the cylinder internals and the water jacket, a compression test should show it clearly.

Supplement his visual observation with a quantitative evaluation, then decide if you need to spend 1K.

(FYI, I recently let a mechanic advise me based on no test and on his experience/observation of a head gasket issue , and paid the 1k. I just paid another mechanic to fix the real problem. The problem was actually a stuck thermostat, a $30 part. FWIW, I agreed with the original tech's assessment, but did let myself be talked out of the compression test. Never again! Take it to another mechanic, if need be, but get the test.)
posted by FauxScot at 11:32 PM on May 6, 2011

Do you get white puffs of smoke out of the exhaust? Does your oil look like milkshake when it comes out? Do you have to refill the coolant reservoir frequently? This could tell you if there is a coolant leak.
posted by Blazecock Pileon at 12:16 AM on May 7, 2011

No need to rush into anything just yet. It is quite possible that the cap is showing the results of a blown head gasket, but maybe not ...

1. Watch the oil on the dipstick - its colour (should NEVER be white-ish), and whether the oil level is climbing (because the sump is filling with water) Either spells 'blown head gasket'.

2. Watch the water level - if it is using water, it is because the water is going out the exhaust pipe (blown head gasket), or because it is going into the sump (blown head gasket). I assume you have checked for other water leaks (while the engine is hot)?

3. Blown head gaskets don't kill cars. No water will, and watery oil will not lube very well. Watching 1 and 2 above will tell you if you have a head gasket broblem.

Good luck
posted by GeeEmm at 12:21 AM on May 7, 2011

Get a second opinion before you do anything.
posted by Thorzdad at 3:59 AM on May 7, 2011

A late thought. If you want a kludge fix, try some of the chemical additive that will (sometimes) seal head gasket leaks. This is not your average 'stop leak' radiator treatment, I don't know what it might be called in your part of town, but here it comes in a black block that you crumble into the radiator. My workshop swears by it. It is not something I recommend, but it is an option.
posted by GeeEmm at 5:59 AM on May 7, 2011

I would get another opinion. Head gaskets can and have killed cars - I speak from experience. Depending on what happens when it really goes, it can pretty much take out your engine (trust me it happened to me).

Having said that, one of the reasons it happened to me was a faulty repair job in the first place. I replaced the head gasket for about $1k, and when that one blew (some debate over whether it was a manufacturer's defect or a faulty repair), I had to replace the entire engine.

It certainly is worth some further investigation, but given my experience with mechanics I would not take it on the word of the first one that it needs to be done.
posted by scrute at 12:28 PM on May 7, 2011

I had a chevy van who always had a little 'goo' on the inside of the oil cap, but when changing the oil there was nothing milky in it, and my mechanic grandfather said that humidity could cause it if something like the valve covers were a little loose, or there was an air gap around the oil fill cap, which wouldn't necessarily mean that there was antifreeze leaking into the engine. Don't assume that's the case, of course, but if the evidence isn't pointing 100% at one cause, there may be many others to consider. so get a second opinion.
posted by AzraelBrown at 1:58 PM on May 7, 2011

Given your driving habits, I would say this is NOT a head gasket problem. What's happening is that the short trips allow moisture to build up in the crankcase of the engine. That's pretty normal. If you were getting coolant mixed with the oil via a blown head gasket, the fluid on the dipstick would look like a milkshake and it'd appear to be overfilled.
Also, don't trust anyone who says that you need a head gasket if they haven't done a cooling system pressure check or a cylinder compression test. The deposits indicate the presence of moisture. Nothing else.

Do this check yourself:
Get an oil change.
Drive the car like you stole it for about an hour.
Recheck for goey deposits in the oil cap. If everything is normal, as I suspect, the heat inside the engine will have evaporated all of the moisture and the deposits will be reduced, if not gone.

Your Hyundai also has a 10 year 100k powertrain warranty. If you do need a head gasket, it should be FREE. If they say it's not, make noise at the Service Manager. You shouldn't have to pay for this repair, in the extremely unlikely event of a head gasket failure.

I'm so confident that you DON'T need a major repair that I'll make the following bet:
If the second opinion thinks you need a head gasket after performing the requisite tests, I'll NEVER ANSWER ANOTHER CAR QUESTION ON METAFILTER EVER AGAIN.

Good luck and don't worry.
posted by Jon-o at 5:17 PM on May 7, 2011

1) A head gasket, when all is said and done, is going to be much more than $1k.

I find that very difficult to believe - especially for the car in question. Perhaps for a V6 or a complicated engine that isn't a 4 cylinder. $100 or so of materials leaves around 7-8 hours of labour even at high rates for an independent mechanic. It doesn't take 8 hours to change a head gasket at all. That isn't a high quote at all for a simple engine like a Hyundai has. If your car hasn't had a major over heating incident, this is a relatively simple (albeit involved) job.

he lifted the oil cap and saw some grey deposits on the inside of the cap.

This is a very reasonable conclusion based on the evidence. The only real part of the engine where water and oil passages get close to each other (that has a weakness) is at the head to block joint (where the head gasket is), so with a rudimentary second check (pressure testing the water system and/or a compression test depending on the other symptoms) you can be confident that it would be the case.

Basically, you're not being strung a line, but additional testing will confirm the diagnosis.
posted by Brockles at 5:22 PM on May 7, 2011

Thank you again, everybody, it's been of great help. I went ahead and cleaned off the oil cap, and will await further oil/water deposits, if any. I checked the coolant level, it's topped off from Friday, and doesn't seem to be leaking, the level is not dropping (so far). Oil dip stick is not showing any milky stuff, just regular clean oil. Nothing is leaking under the car, as far as I can tell, I'll be checking again after a I let it sit for a few days on one spot. No smoke from tailpipe, no smells from the a/c, temp gauge firmly below the half-way point. So, I'll be monitoring the situation, and won't let my lower lip quiver until there are symptoms of something funky going on, at which point I'll have the pressure/compression test before I burst out in tears. For now, it'll be like with prostate cancer, watchful waiting. And Jon-o, now you've prevented me from reporting a definite head gasket problem in case there is one, because I don't want you to stop posting car-related stuff.
posted by VikingSword at 4:23 PM on May 8, 2011

From your latest post, I am thinking Jon-o has it. This sludge buildup used to be common back in the day if cars were only driven on short trips, and the engine had not been hot enough for long enough to evaporate all the condensate that can build up when an engine cools.

Don't stop the 'keeping an eye on it' though, and in the meantime do a bit of research on the most suitable oil for your driving/climate. You might, that if the car is only driven a little, and for short distances, change the oil by time elapsed, not by distance. That is change it every three months for example, not every 5000kms. That might seem excessive, but oil is (relatively) cheap protection, and a DIY oil change is pretty straightforward (do the oil filter as well).
posted by GeeEmm at 11:12 PM on May 8, 2011

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