Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

1998 California Subaru Legacy Outback Motor Siezes After Top End Job

The engine seized on our meticulously maintained 1998 Subaru Legacy Outback, with 111,000 miles on it, just 2,000 miles after a top end job which was performed for the occasion of replacing the timing belt. They replaced the water pump as well. When the car died that day, there was plenty of coolant in the reservoir. The mechanic is trying to say that a slow leak in the radiator made the engine overheat. There was no coolant in the engine. It should also be noted that this was the first long trip that the car made after having it’s top end job.

What should we do? What happened? The mechanic is refusing to take any responsibility. It says on the reciept that he guarantees his work, and will fix faulty repairs. He is refusing us…

Define “top end job.” Are you saying they took the heads off the engine in conjunction with a timing belt replacement? This would be highly unusual.

Coolant in the plastic reservoir, or overflow tank, does not mean there’s any coolant in the radiator or the engine. Is there a leak in the radiator?

If the radiator was leaking for 2,000 miles the engine could easily have lost enough coolant to cause damage, and since you say there was no coolant in the engine I’d say that’s what happened.

Did you check the coolant level before leaving on the trip, or at any time in the 2,000 miles since the timing belt replacement? Checking fluid levels periodically is part of maintenance.

You need to define top end job. Head gasket job or valve job?
If you had a head gasket problem it’s possible the radiator could have been weakened from excessive pressure caused by a leaking head gasket. After the head gasket job the cooling system is now pressuring up and the weakened radiator decides to start letting go.

After 2000 miles and the leaking radiator diagnosis I would say this one is on you; not the shop.

If this engine got hot enough to seize up this did NOT occur in a few minutes. This means you were ignoring the temperature gauge on the dashboard (that’s the norm) and motoring on with some obvious symptoms such as sluggish running, clattering and knocking, etc, etc.

Hmm. No, there wasn’t anything wrong with the engine. These are good replies, though, thanks. So, no, there was no problem with the head gasket, they just went in and replaced the timing belt and water pump. The temperature had been running in the middle and the coolant level looked fine… there was no indication of lost coolant either in the overflow or in the parking spot. When the car started clacking, and pulled over, there was still coolant in the reserve. That is what was wierd. What makes that happen? How could the engine be out of coolant and there be plenty in the reserve if the water pump was still working? (This is an honest question; I want to know if this is really likely. It turns out that this shop has bad reviews all over the internet)


If the head(s) didn’t come off, then don’t call it a "top-end job."
There are basically two kinds of cooling systems, those with non-pressurized overflow tanks and those with just one pressurized tank with enough air-space to handle the expansion. I assume yours is the first type. In that case, this type relies on a vacuum to be formed when the engine cools off, and that sucks the extra coolant back into the pressurized tank. If you have a leak anywhere in the cooling system, this vacuum won’t form, and the coolant in the overflow tank won’t be pulled back in. So, it is very common to find coolant in the overflow tank even when the rest of the cooling system is dry.

It’s going to be near impossible to make a close guess on this one without having the vehicle in hand.

It is possible to have coolant in the overflow tank and an empty cooling system. If one has a slow leak (radiator, hose, whatever) the system may slowly bleed down and not have the ability to draw the coolant out of the overflow tank.
As the coolant in a “normal” system cools off it contracts. This contraction is what pulls the coolant out of the overflow but if there’s a leak in the system then it will simply not pull coolant back in because of the inability to create a little bit of a vacuum.

It’s possible the system was so low that the temp sender may have been unable to provide a signal to the dashboard gauge. This can happen if the sender probe is not immersed in hot coolant. Instead it is simply probing hot air.

The clattering and/or the seized engine could be one of several things.
One is that the shop made a mistake in the timing belt installation and something came loose (valve train, bent valve(s), etc.). This would have nothing to do with lack of coolant.
Two is that a seriously overheating engine can clatter badly. This is caused by detonation in the cylinders and once an engine reaches this stage it’s usually bad news to some degree.

Did the shop screw up here? I really can’t say for sure since there is no way of inspecting the car.
About all I can do is offer some info to help guide this along. Maybe getting another opinion from someone locally there could help clear it up. Good luck.

The plastic coolant reservoir is there to take overflowing coolant from the radiator as the coolant expands, which it does as it heats up. As the coolant cools again, the extra is drawn back into the radiator from the reservoir, IF the system is intact, the radiator cap is working correctly, and there are no leaks.

If the radiator has a leak the excess coolant in the reservoir will not be drawn back into the radiator. The leak allows air to be drawn in instead. As the coolant level drops in the engine and the radiator, the engine temp sensor may not work, since it’s designed to measure the temperature of a liquid which is no longer there.

Do you have any way of knowing if the cooling system was completely full when the car came out of the shop? If you didn’t remove the radiator cap and check the coolant level the answer is “no.” Maybe it was full, and maybe it wasn’t. There is no way to prove anything now.

Please develop the habit of checking vehicle fluids periodically. This can potentially save you LOTS of money in the future.

Thanks, everyone…

The shop put $20 worth of coolant in the radiator when they replaced the timing belt/water pump. It was on the reciept. Also, I do check fluids. I was unaware that there would be coolant in the radiator overflow, but no coolant in the engine. Now I know I guess. The physics of this makes perfect sense to me, but I don’t understand how a person can know that this is happening. The car wasn’t overheating according to the temperature gauge, and there was no puddle of coolant anywhere, and there was plenty of ccolant in the reserve- it was right at the line. The oil was fine, too- I checked that because we were almost due for an oil change. So that is why I was so perplexed that this happened. The car was running perfectly and we took it in for the timing belt, because it was time according to the manufacturer’s recommended maintainance schedule, and before it was even time for the first oil change after, the car was dead.

So- the answer re: was the tank full of coolant when the car came out of the shop? Yes. We paid for that- it is on the reciept.

And, now that I know that the poor car’s engine may have no coolant even though the overflow tank is full, how do I find out for next time? I NEVER want this to happen again!

Assuming that the engine had coolant in it at some point, there was a time when the temperature gauge should have showed that it was overheating.

As ok4450 has said, if the temp gauge sensor isn’t immersed in coolant it won’t give an accurate representation of the engine’s temperature. But if the engine was full of coolant the sensor would have accurately reported the temp. When the coolant was extremely low the sensor would not be immersed and report unreliably. But somewhere in the middle, when the coolant was low, but still flowing over the sensor it should have showed that the engine was overheating.

How do you find out next time?
That’s simple:

When the engine is cold, remove the radiator cap.
You should see coolant all the way to the filler neck of the cap.
If there isn’t any coolant visible, you need to add more.

Since you don’t know how to check the coolant level in the radiator, we can safely assume you don’t know how much coolant was in the engine before you started your trip.

I, however, believe you need to fight with your shop that did the work.
When you stopped your car, was there white steam coming out of the engine?
Did you hear hissing noise after the engine shut down?


I have a feeling something went wrong with the timing belt. tensioner not put on right or the belt was not tight enough. someone needs to remove the front covers for a look.

My Subaru 1998 Legacy Limited 2.5 is in the shop now and has been for 10 days. It has 107k miles. I’ve been having the on/off overheating issues for a few years. If you search the internet “1998 Subaru Legacy Overheating” you will learn that unfortunately many owners have run into this problem. The mechanics that specialize in Subarus all seem to agree that the Phase 1 2.5 engine is prone to head failures when overheated and one of the causes is when coolant/fluid is lost and refilled, air pockets form and can be difficult to clear out. This keeps flued from getting to the heads and this can appear to be intermittent depending on your driving habits. Also, if you have a small leak, and it’s warm then the fluid from the small leak can burn off, so you wont’ “see” any leakage right away and you can get blindsided on a warm day or long trip and loose too much fluid.
The head gaskets seem to be the culprit and if you can replace the head gaskets before the heads are wrecked you are in good shape (they must be genuine subaru parts!)
Not me. I am doing the full engine replacement and the used replacement engine is doing the overheating thing, so we are going in to do the gaskets and look at heads in the replacement engine. Hopefully they are ok otherwise it’s going back and we’ll look for another engine. Prior to agreeing to the engine replacement, we had replaced the radiator (it was bad) and the thermostat ( and it’s housing) and still the overheating issue. Also on the internet you will find procedures about the air pocket issue, sometimes called “burping” the car. I love the car and wish I new some of this stuff 5 years ago. My mechanic is great but not dedicated to Subaru’s so this has been a bit frustrating for us both. Sorry about the long post…I am hoping this info helps others!!! Cross finges and toes that my car issue is resolved before Christmas!!!