So. I think I blew a head gasket

Maintenance/Repairs
1

While I’m not 100% sure, my gut tells me my head gasket is blown on my new-to-me Dodge Durango 5.7. Either the head gasket or the intake manifold. Either way, the other day it seemed to have (thinking about it in rectrospect) hydrolocked, and today I lost about a quart of coolant. I immediately drove it to a garage, which was conveniently located right next door to the Pizzah Hut my wife and I were ejoying lunch.

I figure that since the most expensive part of replacing the head gasket is to remove the head, what other things should I request the mechanic look at/replace if the head gasket is blown? I’m thinking I’ll go ahead and have the lifters replaced since they aren’t terribly expensive and can be problematic on older hemis. Is there any other inexpensive weak-links in there that I should have them change out or more expensive parts to examine while we’re in there?

2

If a lot coolant goes into the crankcase, this can cause starvation of oil to important internal engine components.

Pull the oil dipstick out and check the color/level/and condition of the oil.

If it the oil is overfilled/looks like a latte/ the engine is done

Tester

3

Ask your mechanic for recommendations. I’m not familiar w/that engine. But it is theoretically possible to just replace the gasket, and drive on. But that isn’t usually the recommended procedure. I expect your mechanic will recommend after seeing the condition of the head to machine a little off the top, for a new sealing surface, and restore flatness. They might want to do a complete valve job. Even if they don’t do that , replacing the valve stem seals with new ones might make a lot of sense, depending on the number of miles and age on this engine. Camshaft seals are another replacement possibility.

4

I do not know. I didn’t think about it that much, just drove it to the mechanic. I did pull the dip stick, and it didn’t look like a milkshake. It may have looked overfilled, but, I didn’t wipe down the stick either since I was more looking at the color and opacity.

There MAY have been some residue on the oil cap, looked more reddish/brown (coolant is the red variety) and baked on than milky goo. Looked more like oil kicked up oil to me. I did NOT notice any white smoke, certainly no “gas cloud”. I’ve lost my Volvo 940 this way, and I know what that’s like.

I know it does not take much water in this engine to get it to cut out. A common problem is that without an improved cowling rain water can seep into the intake manifold gasket and cause it to cut out that way. You don’t need a catastrophic gasket failure to cause a temporary hydrolock at idle.

Aside from cutting out and not immediately starting back up yesterday, it’d been running fine. A little bit of a tick which it always had. Never leaked coolant and had a couple mechanics look at it in the last month.

5

@shawn_kearney

From what I understand, leaking intake gaskets are not uncommon on this engine. And leaking intake gaskets can allow a lot of coolant into the crankcase

You have to remove the intake anyways, even if you think the head gasket is blown. At that point, take a very close look at the intake gaskets. If they’re shot and allowing coolant into the crankcase, you’ll more than likely be able to see it

If the intake gaskets are shot, there’s a good chance that was the only problem. And the head gaskets may just be okay

6

@Tester

“If it the oil is overfilled/looks like a latte/ the engine is done”

I’m not sure if you meant this to be a blanket statement. If you did, I don’t agree with it.

I’ve replaced quite a few leaking intake gaskets, because of coolant getting into the crankcase. In several cases, the oil DID look like latte. The engines were not noisey and/or hydrolocked, for what it’s worth. And several years after the repair, these engines were still alive and doing well

I’m not “coming after you”

7

The intake manifold does not seal any coolant passages on the 5.7L Dodge engine.

The engine hydro locked? If a fluid filled on of the cylinders the engine won’t crank over or if it does that fluid will come out the tail pipe. Coolant will create a lot of smoke. There may be another reason the engine stopped and would not crank.

8

@Nevada_545

Thanks for that information

I must have been thinking of a different mopar V8 . . .

:wink:

9

@Nevada_545

I did not notice any smoke, but I wanted to get the heck out the the intersection, too! By the time I got to my son’s school (15 minutes in light traffic) though, there was no smoke.

As for stall, what happened was like this: I came up to the light, sat for a few seconds and then the engine wend “put-put” then cut out completely. I paused for maybe five seconds, turned on the ignition. As I turned the key, there was a sharp brief sharp squeal, then nothing. I thought for a moment that the engine must have catastrophically failed. As a last ditch, I turned off the air conditioner and blowers. The engine immediately came back alive, and actually ran smoother than when the air conditioner was on. Under the hood, there is a slight sound that seems like old bearings or something, so I figured that it was air conditioner-related. My working theory was that when the air conditioner was seized up in such a way that when enabled it drew too much for the starter to turn over.

I told this to the guy at the shop, it was at a dealership so I think he was more just a “car guy” than a certified mechanic, and he didn’t seem to understand my theory. I poked around online, and couldn’t find anything that fit, so with a coolant leak, I assumed it had to be a hydrolock issue.

I guess we’ll see. If it turned out to be a failed hose and the air conditioner is still working it still could be water if the intake manifold is sucking in coolant from outside the engine. I think I might have had a very slight rough idle in a car wash before completely sealing up the cowling (there is a clip that I ran some silicon over to prevent it from dripping), but I thought I was being paranoid. The intake manifold gasket will be replaced no matter what eventually. If it’d a head gasket, I guess I’ll be doing that sooner than later.

Wife reported that the truck ran fine after work, but, she doesn’t keep a good eye on the gas gauge, nevermind the thermostat! Before though, never overheated. I keep a close on on engine temp and the only time it snuck above normal operating temperature was in the mountains, on dirt with the air conditioner on. And even then, it held within rang. I turned off the air all the same, enjoy that woodsy air!

10

Allow me to offer a few clarifications.
Hydrolocking is a condition wherein a cylinder draws coolant or outside fluid into it and cannot compress it, stopping the associated piston from rising up in the compression stroke. Fluid does not compress like gasses do. A hydrolocked engine’s crankshaft cannot be turned and the engine again restarted until the fluid is somehow removed from the cylinder or the cylinder’s “closed” state is changed by removing a sparkplug. Your engine did not hydrolock.

Based on your new description, I’d bet lunch that your air conditioning compressor is seized. It’s drawing too much for the starter to turn the crank, but what it’s drawing is not electrical power but rather energy from the crankshaft. Put differently, the starter cannot turn the crankshaft over to start the engine with the seized compressor holding the crankshaft back.

Post back with your progress. We do care.

11

I think the a/c clutch disengages when ignition is off. When u crank motor, clutch is off. Once motor starts, clutch kicks on. Is clutch stuck on? Don’t think so. OP drove it after incident so if compressor is seized u would still see motor stalling.

12

I agree with mountainbike about the AC compressor

A few years ago, I drove a vehicle when this happened. There was a screeching noise, then smoke. Then the ac compressor seized up and threw the v-belt. I was able to continue, because the belt was only for the ac compressor.

There have also been numerous vehicles at work, where this has happened. And the symptoms were the same

It is not so simple as just throwing another ac compressor at the truck, though. The old one probably shot metal debris through the entire ac system. That means in addition to an ac compressor, you’ll also probably need the condenser. You’ll want to get the system flushed. You want an inline screen installed on suction side of the ac compressor, so that remaining debris doesn’t get sucked back in. You’ll want either the expansion valve or orifice tube, depending on what system you have. And you’ll want the accumulator or receiver-drier, depending on what system you have

Now about that quart of coolant . . . maybe you were already low before you noticed it. Any visible leaks or stains? A good visual inspection and a coolant pressure test would be a good idea.

13

Yes. when I said I lost a quart, it was all over the ground. I thought at first it was transmission fluid, I know I need a gasket replaced and just figured it failed since the coolant was dripping from there. Who thought red would be a good color for coolant? When I got home, that is when I noticed my hands smelled like glycol.

On thing about the AC though - the truck has a serpentine and the belt is still there. We’ll see.

14

Nowadays, coolant can be pretty much any color you could think of

I’ve seen red, yellow, orange, blue, green, and purple so far

Why don’t we just say ROYGBIV . . . that brings back memories, doesn’t it?

anyways, maybe you just have a leaking water pump or something simple

Can you turn the ac compressor clutch by hand . . . with the engine OFF, naturally

Another “test” . . . let the engine idle with the ac off. Now turn on the ac. Does the engine stall or screech? Is the ac clutch even moving or engaging?

15

ATM they are thinking the water pump seized up for a moment. They are replacing it.

16

sounds like they’re theorizing, not diagnosing

:frowning:

17

ATM-I guess that means you will need an Automated Teller Machine after they get done