Author Topic: Older cars that leak oil - how much is "a lot?"  (Read 5083 times)

acepedro45

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Older cars that leak oil - how much is "a lot?"
« on: May 08, 2017, 09:26:56 PM »
Hi Mustache People,

At what point would you deem an oil/engine coolant leak serious?

I have an '03 econobox with ~150k miles. It takes an extra quart of extra oil or so in between oil changes every 5,000 miles. It is also slowly leaking engine coolant and needs a top-off every month or two. I realize these kinds of leaks basically come with the territory of owning an older car, but I am looking for guidance on when I would need to take action.

I am wondering if I should...

1. Invest time and effort locating and correcting these leaks myself. Being somewhat handy and always looking for fun projects, this option has its appeal. Google does warn me that this can be a long and frustrating hunt with no guarantee of success, though.

2. Just keep feeding the car extra fluids and hope for the best. I check this stuff regularly and keep obsessive detailed records on consumption, so I can see the rate of fluid loss is pretty constant over time.

3. Consider replacing the car. Before tonight, I was strongly considering giving the car to my mom in a few months, but I doubt she'd be up for constant policing of the oil reservoir and the coolant levels. Maybe I'm just grouchy about paying $4.25 for a quart of no-name oil at a gas station and overreacting.

4. Getting a mechanic to fix it. I doubt this would be economical considering the market value of the car can't be more than $1,200.

Any thoughts?

checkedoutat39

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #1 on: May 08, 2017, 09:49:57 PM »
Keep recording how often you have to add a quart, and plan for replacement when this interval gets below 1,000 miles or so.

Some engines are well-known for using oil, such as with the old 5-liter Mustangs. Every make and model has a forum out there; you can ask how common this is.

Using coolant doesn't strike me as typical. Might be a bad seal somewhere. First thought would be to get it checked at your next flush.

MayDay

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #2 on: May 09, 2017, 04:46:56 AM »
We had this with our 99 corolla that had about 200,000 miles. Apparently it is a known issue with them. We kept driving it and not worrying about it, as the cars value was very low.

Eventually we replaced the car due to a gifted car from.a relative. We sold the Corolla on CL with full disclosure that it burned oil and it sold.in an hour for $1000. People are crazy.

MightyAl

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #3 on: May 09, 2017, 04:55:08 AM »
Now is it consuming fluids or leaking them?  Consuming a quart of oil between changes on an older car can be considered normal.  Leaking out a quart of oil between oil changes is not good.  Depending where it is leaking is a cause of concern.

Consuming coolant is bad and leaking coolant is usually pretty easy to diagnose and resolve.  If your engine is consuming coolant then you have a headgasket going bad and the engine is on borrowed time.

So the lesson here is that consuming oil is ok and leaking oil is bad, consuming coolant is bad and leaking coolant is not that bad.

chemistk

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #4 on: May 09, 2017, 05:36:27 AM »
For the oil, it sounds like your engine is consuming it, not leaking (you would see a spot on the ground).

Now is it consuming fluids or leaking them?  Consuming a quart of oil between changes on an older car can be considered normal.  Leaking out a quart of oil between oil changes is not good.  Depending where it is leaking is a cause of concern.

Consuming coolant is bad and leaking coolant is usually pretty easy to diagnose and resolve.  If your engine is consuming coolant then you have a headgasket going bad and the engine is on borrowed time.

So the lesson here is that consuming oil is ok and leaking oil is bad, consuming coolant is bad and leaking coolant is not that bad.

This is some good advice, but I'd also couple it with

Keep recording how often you have to add a quart, and plan for replacement when this interval gets below 1,000 miles or so.

As engine internals wear, oil consumption increases and is something that just happens as a result of regular use. Some engines are better, some are worse. The best thing you can do is to keep up with regular oil and filter changes. Definitely keep track of specific usage amounts (not just an estimate).

For the coolant - I don't necessarily think your head gasket is leaking, but it would still be something worth taking to a shop and have them investigate it. They can add a fluorescent compound to your coolant and have you drive it for a while, then bring it back in and they can use a black light to see where it went.

acepedro45

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #5 on: May 09, 2017, 07:15:28 AM »
Thanks for all the good advice.

From this thread, I am thinking I should prioritize the coolant leak. I was reading/Youtubing last night about diagnosing them. I understand a pressure test is a good way to spot coolant leaks and the needed tool can be borrowed for free from AutoZone, so....I guess I'll give it a shot. Nothing to lose, right?

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Now is it consuming fluids or leaking them?

I am not sure on this one. I don't have a regular parking space, so it's harder to monitor the ground for signs of spills. I will try be more watchful. I did read enough to check the engine oil for milky traces of coolant, and I didn't see anything. In my limited understanding, that lessens the probability of a bad gasket (phew!).

Syonyk

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #6 on: May 09, 2017, 08:39:13 AM »
It just means your coolant isn't leaking into the oil. It could still be getting into a cylinder (also bad).

1 quart every 5000 miles is firmly in acceptable territory, even if it's leaking it out.

A quart every thousand being burned used to be considered acceptable.

I'd start thinking about repairs around the quart per 500 mile range.

daverobev

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #7 on: May 09, 2017, 03:07:17 PM »
Thanks for all the good advice.

From this thread, I am thinking I should prioritize the coolant leak. I was reading/Youtubing last night about diagnosing them. I understand a pressure test is a good way to spot coolant leaks and the needed tool can be borrowed for free from AutoZone, so....I guess I'll give it a shot. Nothing to lose, right?

Quote
Now is it consuming fluids or leaking them?

I am not sure on this one. I don't have a regular parking space, so it's harder to monitor the ground for signs of spills. I will try be more watchful. I did read enough to check the engine oil for milky traces of coolant, and I didn't see anything. In my limited understanding, that lessens the probability of a bad gasket (phew!).

Get car hot, park, put large piece of paper underneath with a rock holding it down? Newspaper, 4 rocks, etc. Should be pretty easy to see.

HipGnosis

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #8 on: May 09, 2017, 06:46:29 PM »
My grandfather and father were professional mechanics.  I've been working on engines and other mechanical things (started with farm tractors) for 40+ yrs (not professionally).

I'd rather have a car that leaks oil than one that is burning oil. 
Leaking oil is probably a bad gasket.  Pretty low chance that it'll suddenly start losing more.   
Burning oil is due to a mechanical imperfection / malfunction.  It could get quite worse quite quickly, and even destroy the engine (if it happens at high RPM).

Antifreeze into a cylinder would create very noticeable white(ish) smoke out the exhaust.  And it has a distinct smell.

One way that might tell if you're burning oil; drive at night, wait until a car is behind you (but not right behind you), with their lights on.  Downshift and give it full throttle. Let off the gas for a couple seconds and give the gas again.   Look in your mirrors.  Oil smoke will be blueish in the cars headlights.

highflyingstache

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #9 on: May 09, 2017, 07:21:56 PM »
The other thing to note of oil, albeit many fluids exhibit this; it can look really bad, or not at all. I don't specifically look to cars, but if you see a good pool of fluid, most oils will spread over an engine, the surrounding panels and can coat quite quickly, although they're not actually going through much oil at all. I leaked through a quart an hour on a 180hp engine, some time ago...want to talk about a lot of oil everywhere...that was a mess, extremely notable.
Even if you see quite a mess (mentioning 1 qt every 1000 km/miles) may not be as such. Lots of great advice above on what actually happens; however the crux being, trying to find the leak can be a real pain when it really does go everywhere, especially as airflow can push it around and gravity helps it can essentially get everywhere. Only by cleaning the workplace, i.e. the engine and oil lines, can you probably start to take a stab at finding the source to fix that leak.

Syonyk

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #10 on: May 10, 2017, 09:21:07 AM »
Burning oil is due to a mechanical imperfection / malfunction.  It could get quite worse quite quickly, and even destroy the engine (if it happens at high RPM).

<.<  If your engine is suddenly burning enough oil to destroy the engine at high RPM, you'll notice.  I fogged out all 4 lanes of I-80 when an oil seal let go on a rotary engine of mine.

In general, I don't mind an engine that's burning some oil (well, ok, at this point in my life I mind a bit, but I'll still run it).  If it's coming past the rings, the engine is worn but as long as it'll start, it's fine, and if it's coming past the valve guides, eh.  It probably won't get worse that fast, and it's not that likely to coke up enough to stick a valve on an automotive engine.

Quote
Antifreeze into a cylinder would create very noticeable white(ish) smoke out the exhaust.  And it has a distinct smell.

Yup - also usually obvious on a hot restart on a warmer day.  You'll get a puff of white smoke.

sisto

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #11 on: May 10, 2017, 09:55:59 AM »
I used to have a Ford Ranger that burned a quart of oil between oil changes even while still under warranty. The dealer told me it was within acceptable limits. I always thought that was terrible for such a new vehicle. On the other hand I've driven older vehicles that burned oil just from being old a little blow by past the rings or some minor seal leaks. What you described doesn't seem that bad. I think just keep up on checking the levels.

sequoia

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Re: Older cars that leak oil - how much is "a lot?"
« Reply #12 on: May 10, 2017, 10:14:35 AM »
Are you leaking oil
- into the engine (the oil is getting burned by the engine) - this might be a bit more involved to fix but at your rate I am not worried. Do check your oil level regularly just incase it starts using more oil, and you do not end up driving around with no oil in the engine.
- to the outside the engine (you park and your car is dripping oil into the ground)? If this is the case, where? It can be as simple as tightening some bolt. My Land Cruiser is known to have top cover bolts that need tightening to stop leaking. Not even 5 min work to fix it.

Same with coolant. Leaking into the engine is a more complex problem to fix, but leaking to the outside maybe as simple as replacing a rubber hose (cheap), tightening a hose clamp, or need new radiator. I would prioritize coolant leak first.

« Last Edit: May 10, 2017, 10:18:32 AM by sequoia »