Hey all,

This is more just a general information question, as I've been doing a lot of reading on D2 maintenance and have been trying to educate myself on the ins and outs of my truck.

Could anyone lay out for me what head gasket failure looks like practically? What are the symptoms, how might they progress, what are the causes and how serious of an issue is it? This layman appreciates the help. If there's already a post on this, please link--I couldn't find it.

I only ask because my truck has been dripping oil, most visibly from my valve covers, but I recently got an oil change and noticed that I am now dripping/burning much more oil than I was before. I got my oil changed about 3 weeks ago; 2 weeks ago, I made a 1 and 1/2 hour drive to OKC and back, and this weekend I drove about 50 minutes and back, and driving around town daily. I checked my oil on my last trip because I noticed I had oil dripping in three different places . I was below the "low" marker. Picked up some Pennzoil 5w-30 at a gas station and poured the whole thing in, put me up to about halfway between low and full.

I supposed I need to clean my engine up to see where my leaks are coming from, but without much in the way of tools or a place to work, I may just take it into my local mechanic and see if he can diagnose it for me.

 

burning? are you seeing funky smoke out the exhaust? rings can cause this too.
some common hg failure symptoms would be a mixture of combinations of coolant/oil/exhaust and or some leaking. exhaust usually makes that quick chicka chicka chicka sound below manifold.
but yeah first step is get to cleaning. many times the valve covers can be tightened with out replacing gaskets and that will fix that.

 

That sounds like just a valve cover gasket problem. Doesn't get easier to fix, but it's probably getting pretty messy since it's not been fixed.

A blown head gasket usually means the gasket is blown out around the coolant jacket so that engine coolant is blowing into the cylinder where it blows out the exhaust and into the oil. You get a milky oil/water emulsion in your oil pan and a rapid loss of engine coolant in the coolant system/surge tank/radiator.

 

While your immediate problems are just an oil leak, the engine in your car probably has a crack in the cylinder behind the liner where the head bolt pulls on the alloy part of the block to clamp the head on. Some estimates suggest that most Bosch-equipped engines are cracked.

Over time, you'll see gradual coolant loss as the coolant is leaking into the cylinder and blowing out the exhaust. The coolant loss will accelerate over time as the crack enlarges with high temperatures. Eventually the head gasket will blow and the problem won't be unnoticed anymore. But the blown head gasket is just a symptom of the real problem. You can replace it, but the coolant loss will continue until it happens again. The only "permanent" or long-term solution I've heard of is to remachine the block for "top-hat" liners. Those liners have a broad top flange that seals against the head so the cracked block can't blow coolant into the cylinder.

Sometimes the cracked block is diagnosed as a "slipped liner." The real problem isn't that the liner is slipped, but that a crack behind the liner is blowing coolant between the block and the liner out through the top of the liner. The top sealing of the liner fails because there's pressure under it from the cracked block leak. I am pretty sure the "pinning the liner" solution won't solve the problem.

 

The jedi powers are strong in these lads.

But perhaps all is not lost.

Oil leaks are frequently cured by snugging up the 8mm 12 point slim socket bolts on the valve covers.

HG can leak - external coolant, usually front or rear because that is where gasket has least "meat" around the coolant channels.

Can leak into cylinders, make misfires, white smoke out the exhaust, steam clean the plugs.

Can leak into the oil, make oil level higher on stick, and a milkshake color in oil drained. Less often as there is only one oil path thru the head gasket. Coolant in oil rapidly trashes main bearings.

Can leak external, sounds like exhaust leak. You can locate with a length of rubber hose, move along edge while listening thru it. External leaks try to cut a groove in the engine block, repair promptly.

Loss of coolant from all these can cause significant overheating, to the point the cylinder sleeve breaks loose from position and begins to slide up/down.

The root cause of HG leaks can be a lot of things:

Electrolysis

Poor installation of previous gasket

Re-use of used head bolts

Quality of gasket itself

Frequent wide temperature swings when operating with poor cooling system components (sludged radiator, etc.)

Operating more than 100 meters from the factory

I have 189K on a 97. I had to do HGs due to external leak. But found plenty of other problems. And the HGs had been done some time before I bought the truck, the heads were different color (red vs black) oil crud compared to the block. I like to run cool and constant temperature. I run a 180F stat.

If DIY HG in your future, $200 for parts, including new bolts. Another $250 to have heads machined flat and valve job done with parts from your gasket kit. As for labor, depends on how many mistakes you make. Many do it in two weekends with shop work in between. Some can do it faster, and some take their time. After compeletion your Rover man card may be punched for that task, and meat roasted to honor the Rover gods.

 

gets my vote

 

I don't see any smoke in my exhaust thankfully. The burning assumption just comes from smell; when the car is running, it smells like a frying oil pan if you're standing around it. It's not horrible, but it's enough that I've had a stranger at a gas station knock on my window to let me know it smells like I'm burning oil (thanks, genius).

I have been losing coolant. I recently had my radiator flushed, and the mechanic told me there was no sludge, that the coolant was very pure, but that it looked like it had been watered down (I bought the truck from PO like 2 months ago). So it looks like I'm losing coolant somewhere. I don't hear a chicka chicka sound though. I'm thinking it's probably just the valve covers too... at least I hope!

 

There's a layer of pretty dark, thick oil surrounding the seal of the valve covers. I hadn't noticed milky oil. But I definitely am losing coolant.. is there anything (additives, etc) I can do to try and avoid a potential blown HG?

And I was thinking the valve cover gaskets would be kinda tough to change by the look of things, at least compared to my old Duster's 360. Obviously much easier than HGs, but still not something easily accomplished in my apartment parking lot lol.

 

frying is probably the valve cover leak onto manifold. need to address that one. it can also get to plugs and cause miss.
coolant= curious, are you only loosing is to a certain point in the expansion tank?
I only ask because my 2 current d2s suffer from only wanting coolant to be at about 3/4 to 1" below the predetermined fill level line. if i fill more, it gets very slowly forced outta the overflow. I use a permanent marker and make my own sloppy fill line.
but also you can get a test that will show if you have exhaust getting into coolant. it changes color is so

 

So, how do you guys go about cleaning your engines? I've read you don't just want to take a hose to it, but what cleaner/utensils do you all use?