CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Catalytic converter

Took our 2005 Subaru Forrester 79000 miles to subaru dealership mechanic 21/2 weeks ago after the check engine and cruise light kept coming on and off.



They checked it and reset the catalytic converter but said that it the lights would probably come on again and to bring it back in becuase that is under warranty up to 80000 miles.



The lights came back within the week, brought it back. They replaced it. Yesterday, 12 days later, driving on the highway the car started not responding to the accelerator and check engine light only came on and car. We pulled over and tried starting it. The engine stared but it was bucking.



We were towed the final 60 miles home, devlivered it back to the dealer/mechanic, who thankfully were open… and he checked the oil and found NO OIL…



So, have we had a leak for a long time that was detected when I brought it in with the check engine light on? Or in replacing the catalytinc converter did the mechanic make a mistake and do something to the oil line/tank??



We did notice a few spots on the street where we park the car today when thinking about this problem. We won’t know until Monday the prognosis, but it sounds pretty certain that the engine is wrecked.



We have regularly serviced this car with oil changes every3-5ooo miles, the guys who do that would have seen a leak no doubt? We recently had new brakes/ brake flushing done, might a leak have been noticed then?



And why wouldn’t the Subaru mechanic check the oil when we brought the car in or before it left after the catlytic converter was replaced.



I really feel that they are the ones who have destroyed our car and we intend to get them to own up to this.



Anyway have any advice? Or know anything about how an oil leak could have happened during a catalytic converter replacement?



Quite upset and gearing up for a battle.



I’m sorry, but the car’s OWNER is responsible for checking the oil, and all other fluid levels, periodically, so stop looking for someone else to blame.

The catalytic converter replacement has NOTHING to do with the lack of oil. Perhaps they should check fluid levels on all cars, but obviously they don’t, and the CC is part of the exhaust system, under the car. They may never have opened the hood.

But then you never open the hood either, do you? Engines that leak leave tell-tale traces of oil under the car, but they might not be very big because most of the oil leaks out while the car is in motion. That’s why there’s a black stripe down the center of the road. It’s OIL from leaking car and truck engines.

If you had been checking the oil once in a while, you would have noticed the level falling, and you could have prevented this from happening. It takes 30 seconds to check the oil, and you shouldn’t get dirty doing it.

This is going to be a very expensive lesson. I just hope you learn from it and don’t make the same mistake in the future. ALL cars, even new ones, should have their oil and other fluids checked, at least once a month and preferably more often than that.

Now, depending on how the car was transported 60 miles, you may have another problem.

A Subaru that needs to go 60 miles but won’t move under its own power should be carried on a flatbed truck.

Subarus should never be towed more than a few miles, at low speed, and only after deactivating the AWD system by inserting a fuse in the AWD socket under the hood.

If this car was towed with 2 or 4 wheels on the ground there could be (probably has been) significant damage to the AWD system, which won’t show up until the engine problem has been solved.

I only tell you this to help you avoid a nasty surprise. The situation is bad enough already, you don’t need more trouble.

I hope the car was transported properly, and you only have to deal with the engine issue.

By the way, I once ruined an engine by ignoring the oil pressure warning light. It was an expensive lesson, but I learned. I have a car that has never leaked a drop in the 10 years I’ve owned it, and uses no oil between 5,000 mile changes. I STILL check the oil every two weeks. Just because it hasn’t leaked yet doesn’t mean it never will.

How many miles before the incident did you have your oil replaced?

I don’t think they should check the oil level unless you tell them to do so, or they promise to do it as part of any routine inspection on all cars in the shop. Some places do that to see if they can drum up more business. If they check fluid level on every car in the shop, you have a reason to suspect they goofed.

Can’t you find a dealer closer to you?

Sorry, couldn’t resist.

Mcp nailed it.

I would definately try to find another dealership. These guys sound like they’re ripping you off. First of all, if the check engine light comes AS WELL AS the cruise control light, how on God’s green earth did that lead these morons to a catalytic converter? The converter will not directly cause either of these lights to come on. Plus, they KNEW it was not the problem because they said the light will probably come back on. Sounds like these guys can’t diagnose a dead cow. By the way, most cars have a separate “idiot light” for oil and a separate light for the “check engine”. Does yours? Did the light ever come on? The oil thing is something that may have happened suddenly if you “blew” something. there may be a huge oil spill 60 miles back. And how do you “reset a catalytic converter?” There’s no such thing. Tow it 60 miles the other direction and find someone else at their expense.

Two things… we had to be towed 60 miles to get home and the dealership is in the next town… secondly I have regulear oil changes and never have been low… so this has occured only since the cc replacement… or was the reason the check engine light and cruise light was coming on and they failed to figure that out.

And not once did the oil light come on?? And yes it was transported properly on a flat bed …

The dealer is in the town next to us we were traveling home and broke down 60 miles from home… thanks.

No oil light came on… which is stange I think, and I would like to have it taken to our original dealer becasue I suspect that they will do their best to cover up their mistake. Have regular oil changes and never has it been low so why would I suspect that it would be now, especially if no light came on.
They did replace the cc tho, and that may not have been the problem… and don’t you think that if the check engine light comes on then they should CHECK the engine fluids first??
Thanks for your comment.

The Cruise Control flashes in Subaru’s when the CEL is on for most codes as it becomes disabled(perfectly normal). A CEL is very indicitive of the likely Cat Converter and it is covered by the Federal Emmissions 8yr/80k warranty.

If not replaced yet seek the dealer out.

OK. Good. At least as far as the towing is concerned.

Now I have to ask, since you didn’t check the oil level yourself, how do you know the dealer isn’t lying? If they claim there’s no oil in the engine, and you have nothing which with to dispute their claim, what are you going to do?

Perhaps the engine is full of oil, or at least reasonably full, and they are using this as an excuse to make you pay for a new engine. How will you ever know?

The fact that the oil pressure warning light never came on is disturbing. If there really was NO OIL, the OP light should have come on. Actually, it should have come on long before there was no oil, which brings me back to my theory that someone is not being entirely truthful.

Have you kept maintenance records? If you can prove when oil changes and other routine maintenance was performed you might have a chance, since the vehicle is not very old. Otherwise, you’re going to have a difficult time convincing anyone of anything.

I’m really happy to hear the car was transported on a flatbed. You have no idea how many people kill their Subarus by allowing them to be flat-towed because they don’t know any better.

Ii still can’t make a connection between the cat replacement and the oil problem (if there really is an oil problem). Sorry, but that’s a stretch.

No the guys who change the oil would not always notice a leak. They get paid to change the oil. If you are using a quick oil change place, they get paid for changing the oil really fast and if they stopped to look for leaks they would be out of a job that same day.

It is your responsibility to check the oil level.

I hope you are still with me because I have another one. You may have been burning oil. You would not have noticed much smoke because the converter was eating it, until it finally died due to all that oil. In other words, you could be held responsible for the converter and it may not be covered under the warranty.

Sorry, but I guess this one is only going to cost you inconvenience and money.  No one was injured.

We saw the mechanic pull out the empty oil stick… and the coolant was empty as well…They just called and said that the spark plugs are bad and the wires and ignition coil need to be replaced before they can get the engine started to diagnose the problem. We had the spark plugs done at 37000 miles, and they say we should have had them done again at 67000… is a new car so sensitive that right on the button the parts conk out???

Don’t think I want them working on the car. Not sure what to do…???

We live in a small town and the oil guys are attentive. The cc was replaced under warranty and I doubt very much that the oil has been leaking that long.

Don’t know how to proceed…

We’re trying to be as truthful and helpful as we can; though, it may seem that we are being harsh. The questions we ask aren’t nearly as harsh as some others will ask you.
You say that the oil level hasn’t been low. Since when, and how do you know?
Possible scenario: at the last oil change, the oil drain plug was left loose, over-tightened, or, had bad seal (gasket?). Since then, oil has leaked. Ok. Prove it to them (oil-change place, or suitable authority). The time, and mileage, since that last oil change matter, a lot. If hundreds, or thousands, of miles ago, you have no case.
The claim, now, is that the engine has no oil. This is an assumption. One would know how much oil is in the engine by removing the drain plug and measuring whatever came out.
“The oil pressure light didn’t come on.” This could be true if the oil level didn’t get low enough for the oil pressure to drop and turn ON the low-oil-pressure light. One and one half to two quarts of oil are enough to maintain oil pressure. This is a bare-minimum level, but, it won’t kill the engine (at least, for awhile).

There was one drop of oil on the end of the dip stick… nearly bone dry… so why didn’t the oil light come on???

The last oil change was 5000 miles, just time for another now. It could not have driven that long with a leak? That receipt said that the coolant level was fine and the oil was changed… there wasn’t coolant either??? They called and said that the spark plugs, wires, and ignition coil need replacing to get the engine running before they can diagnose what is going on in the engine.

Does the oil line go anywhere near the exhaust so that they might have knockced it loose when doing the cc???

AM looking for a different mechanic right now to have it taken there.

The leak doesn’t have to be outside the engine. If it’s inside, you’ll just burn the oil.

The oil dip stick only reads (has oil on it) when the oil level is above two, or three, quarts. So, no oil on the dip stick doesn’t mean that there isn’t ANY oil in the engine. Once again, the only way to determine the amount of oil, is to drain it.
Your engine holds, about 5 quarts of oil, when filled to specifications. Car makers consider lose of motor oil, from burning in the engine, up to 1 quart per 1,000 miles to be acceptable. So, at that rate, you car would be allowed to lose 5 quarts in the 5,000 miles since your last oil change (ALL of its oil)! You don’t have a leg.

Really, so if never before has this car noticably been low on oil at our oil changes then it is not unusual now for it to have lost all of it’s oil in this time…??? That doesn’t make sense… The reason I took it to get service is because the check engin/cruise light came on… so they should have checked the ENGINE…not just hook it up to a cmputer and read some readout… not buying it… they were the lst ones to touch this car…no other alarms were raised… no hot engine gauge, no revving, no hesitations… running as per normal… out of the blue 12 days after a new catalytic converter adn we have no oil and no coolant… sorry… doesn’t sit right with me… nope.

And, you know for a fact that the oil level was at the full mark 12 days ago when the catalytic converter was changed? The mechanics are NOT charged with checking the oil level when they do other maintenance on a car.
YOU didn’t check oil level, at any time, during 5,000 miles of operation. And, yet, you say that it hadn’t lost any oil in any way, up to 12 days ago! Where is your substantiation?

Jt Sanders Is Correct When Stating, “The leak doesn’t have to be outside the engine. If it’s inside, you’ll just burn the oil.” It Sounds Like The Catalytic Convertor Went Bad Because …
… of all that oil and coolant being burned (but not completely burned) in the engine. Convertors can burn minor amounts, but not massive infusions. The reason for the internal leak is probably a failed cylinder head gasket or other related component. It could have failed first or another problem with the cooling or lubrication system could have caused its demise. Virtually no oil or no coolant can do it, too. It’s very possible the dealer did nothing to cause this. They possibly could have checked into a resaon for a failed convertor, though, while replacing it. However, I’m guessing this vehicle was out of warranty by then. Is this correct?