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Oil Leak Dye Detection Test: Is it worth the cost?

I took my '04 Ford Focus to a dealer today to get an oil change and a tire rotation. The technicians found an oil leak and offered to run the diagnostic test where they insert dye into the engine to see where the leak is coming from. The test costs about $120 and I’d like to know if this is worth the cost. I have a mechanic I trust around here who says that test is unnecessary b/c all you need to do is wash the engine and run it for a bit. If there’s a leak, you’ll see where it’s coming from. To say that I’m not a car expert is an understatement and I deferred to my regular mechanic. But, I would like to know anyway if there is or are any reasons for why that test would be worth such a cost.

In the interest of full disclosure, the car has about 69,000 miles on it.

Using the dye to locate an oil leak is a last resort. Your mechnic is right. You first wash the engine and then try to locate the oil leak. The only time the dye is used is if it’s very difficult to locate the leak. And it shouldn’t cost $120.00. More like $20.00. And that’s only because the dye isn’t cheap.


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Cool. Thanks Tester!

+1 to Tester’s comments.

Besides, a bit of oil weepage if the car is high mileage is normal and harmless, as long as the level is kep above FILL and you’re not getting spots on the garage floor. If you’re leaking an excessive amount, or your garage floor is getting spotted, post back.

Otherwise, ignore them. Yours would not be the first car brought in for an oil change wherein the dealer “finds” $3000 worth of work that “needs” to be done. 99% of the time the “oil leaking” problem is bogus, unless of course your level truely keeps dropping.

An oil leak severe enough to need repairing is usually severe enough to see dripping. If there is no puddle on the spot where the car is usually parked there probably isn’t a problem.

But a lot of people LIKE their garage floors!

Sertiously, I agree with you Rod. It irritates me to think about how many people are spending large sums of money that they cannot afford to get “problems” corrected that aren’t really problems at all.

Speaking as a PROFESSIONAL technician, if a customer brings me their vehicle with the complaint of an oil leak, dye is the FIRST resort. Why? Because it’s always a possibility of more than one leak, I like doing an accurate job, And it’s MY boobie in the wringer if it’s not fixed when it leaves! But seriously, if you didn’t take it in for a leak then pass. It’s obviously not a problem for you.

In a pinch, if you don’t quite see where the leak is coming from, clean the area off and spray some baby powder or cornstarch on where you think it may be coming from.
After you start the car and air starts moving around the engine, the powder sticks to the oil and will cause the trail to be readily visible.
If anything, it will make your car smell like a baby.

Not sure how to spray cornstarch; use an aerosol can of athlete’s foot powder on a power washed engine; you’ll find the leak and have enough left over to keep your toes from itching.

Well, corn starch is really sprinkled because of the packaging it is in but baby powder is easily sprayed. It works well on all fluid leaks. It being an old trick, it is time tested - mother approved.

I’d like to make a point in support of all those who’ve stated that if it isn;t causing any kind of problem for you than just ignore it. Unless oil is dripping onto a hot exhaust surface and burning, or it’s being ingested into the intake, or it’s causing an unacceptable condition on your garage floor, or it’s leaking at such a rate that it keeps running low, than leaks do not affect the longevity of reliability of the engine.

Your engine’s oil is in an open pool in your oil pan. The oil pump draws it up and pushes it under pressure through various channels in the engine to places where it’s needed. It then simply drips back into the oil pan pool. As long as the level doesn;t go below the pump’s “pickup”, the engine remains fully lubricated and runs just the same as it would if you DIDN’T have some oil on your engine’s bottom.

I’ve attached a document that hopefully will help explain it. Hopefully it’ll help you sleep better by knowing that these “leaks” (printed with skepticism) mean nothing, as long as you routinely check your oil as you should be anyway.

I mostly agree with mountainbike with just a small caveat. As the oil level gets lower, the oil is cycled through the engine more frequently and therefore runs hotter. One qt down isn’t much of a problem but as you go lower, the oil will get much hotter and be prone to sludging up your engine.

If you are losing less than one quart between oil changes, you don’t need to do anything except monitor your oil level when you gas up. Same if you are losing less than a quart per 500 miles, but you just have to be more diligent on the monitoring and keep the level always above the add mark.

If you are losing more oil than that, you won’t need a dye to find the leak. Just follow the trail of wet oil on the engine. Find what is leaking, get estimates to fix and then determine if it is cheaper to fix vs adding oil. Some leaks are easy (cheap) to fix, some not so. Be aware that when an engine is leaking oil at this rate, it can get a lot worse on a moments notice.

Sometimes a more expensive repair can be combined with another repair. For example, if it turns out that the front crank and cam seals are leaking, thats an expensive repair, but if you are due for a timing belt replacement, then doing it at that time doesn’t add much to the total cost of the timing belt job.

Well stated Keith.

I’d also like to add to my previous set of situations wherein an oil leak DOES require attention one more: the main seal. If oil is leaking out the front on an engine with a timing belt, it needs to be addressed. Oil seeping past the front main seal can and will damage a timing belt.

Anyway, I didn’t see that in the OP’s post. My tsrong impression is that the shop recommended unnecessary expensive gasket replacement with no real purpose other than revenue generation.

Only 8 years old and only 69k miles, I think you are right.

Gosh these are old posts but i hope someone can reply with some thoughts. My 03 Suburban has 240K on it. I do ALL the work on it so am very familiar with almost all aspects. This vehicle uses a quart of oil every thousand miles. There are no leaks on the ground at any time. I do not see oil on the rear seal. I replaced the front crank seal and there is no oil there. I replaced the oil pan gasket as well and no apparent leak there. I replaced the oil sending unit. I replaced the valve cover with a redesigned one that was supposed to address oil usage. All of this over past few years but to no avail on finding out where this amount of oil is going. There is oil on the pan that gets pushed all the way back due to wind but again not enough to drip or make any puddles/drips on driveway whatsoever. This leads me to believe that there are only two things left that could be doing this. 1) the timing chain cover and/or its interface with the oil pan. I can’t imagine this amount of oil going away with a leak in the timing chain cover. I do not see any leaks when observing the area while engine is running for 10-15 minutes. 2) the engine is burning this oil. I am at a lose and suspect it is burning the oil but i would think at that amount you would know from exhaust that there is burning oil. Other than that, could it be that it is dripping/leaking only when the vehicle is actually moving? I really would like to put this to bed and understand where this amount of oil could be going. I have religiously changed this oil every 3K and am the original owner. Thanks for any insight!!

If you can’t SEE and leaks anywhere on the engine, it is not leaking. The dye is to pinpoint a leak you KNOW you have but cannot find the source and don’t want to tear everything apart - like you did - to seal the leak.

Run a warm engine compression test. Both wet and dry. I suspect the rings or valve seals are worn. If it has good compression, the valve seals need changing. Not a horrible job on a pushrod LS Chevy.

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At 240K yes it probably is burning that amount of oil. No blue smoke for two reasons. I don’t care to do the math but off hand would guess it’s greater than 100 to 1 ratio gas/oil. The excess hydrocarbons are being taken care of by the catalytic converters.
To dispose of some 50/1 mix from my boat I put it in my 4 cycle lawn mower, no blue smoke.
At 240K, 1000 miles per quart seems quite reasonable.

Next time though, suggest you start a new thread, not piggyback on a 6 year old thread.

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Assuming 18MPG, 1qt per 1000 miles is 222:1 gas/oil ratio.
1qt per 1000 miles isn’t bad for an (V8) engine that size.
I’d be more annoyed if a 4 cylinder of half the size were burning that much.
1qt per 1000 miles leaking would likely make a big mess.

First, I think you need a little perspective here, 1 qt/1000 miles is really nothing to get worked up about. From an economic view, the lowest cost alternative is to check your oil level every time you fill your gas tank and top off as needed, plus your regularly scheduled oil changes. The time and money spent on new gaskets etc will easily cost more than just topping off the oil as needed.

I don’t see mention of the PCV valve so if you haven’t checked it for a rattle, you probably should do that.

But if you are seeing this as a challenge, man vs oil leak, then step one is to clean the engine as much as possible. Get under there with a degreaser and remove all dirt and grease/oil. When it is clean and dry, put a little talcum powder (baby powder) onto suspected areas. Within a couple of days, you will see the leak. BTW, you can use a quart of transmission fluid instead of a dye as the red color of the transmission fluid will really show up when it hits the talcum powder. Don’t overfill the oil pan though.

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