FJ62 3F-E Possible Blown Head Gasket? (1 Viewer)

[vankho]

Hi all,

I'm a relatively new 1989 Land Cruiser owner (3 months!). Basic auto maintenance experience such as oil changes, brake changes, fluid changes, etc. It's been a ton of small projects so far, that might be good for future build thread, but the latest round of symptoms is throwing me for a loop and keeping up tonight. Love to get everyone's thoughts and strategies.

I recently got a new exhaust system installed (new cats, custom y-pipe, OEM muffler and tailpipe) which I thought would solve a lot of issues since there were exhaust leaks, rattling and being held together with tape and JB Weld. But driving back I was just keeping a keen eye, ear, and nose to how it was running from the muffler shop... and I'm started to smell something relatively sweet.

Then it reminded me of the times I've had to refill the coolant reservoir ever since the coolant fluid change. Inspecting for a coolant leak is on my to-do list. Then it reminded me of the puffs of white smoke from the exhaust (before the new exhaust system). Quick research leads to anything from coolant leak, blown head gaskets, warped heads and blocks, to just tossing the engine.

Where I'm at now, is like reading WebMD for what you think is a small symptom and finding out you are going to die. Where should I begin to start narrowing down this diagnosis?

 

[surfcraft3]

We are in the exact same situation unfortunately. Best advice I can give you is to have a compression test done to determine if there is a blown head gasket. Pull each spark plug to see if any of them are really fouled. I have 4 cylinders that are reading 145 and two that are under 40. There were all kinds of adjustments made to the fuel and air flow to compensate by the previous owner(s) but it finally got so bad that I was unable to drive it. Taking it in to have the gasket replaced in a few weeks. Best of luck with yours!

 

[Seth S]

a compression test is a good place to start. If the compression test doesn't show anything obvious then you can ask a mechanic to test for exhaust gas in the coolant. You can also pull out your oil dipstick and look at the oil. If the oil looks clear (more recent oil change), or black (maybe need) then thats a good sign. If the oil on the stick looks like chocolate milk then you have coolant in the oil.

 

[partytime]

Request a kit from blackstone labs and get your oil analyzed. This is the best way to know definitively if you have coolant in the oil or not, its only like 20 bucks

Blackstone Laboratories Blackstone Laboratories

Learn what's going on in your engine with oil analysis. Our free kits are easy to use and we explain the results in plain English!

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You won't know if the head gasket is blown or the actual head is cracked till you take it apart, unfortunately on these cars a cracked head seems to be much more common than a blown gasket.

I just replaced my cracked head, gasket was fine but head had a visible crack in it.

 

[Michael Hanson]

Hi, Check your anti freeze, if it’s not green or red but brown or dark, you probably have a blown head gasket. Check for bubbles in the over flow. Mike

 

[vankho]

Thanks everyone for your help and advice. I finally found time to check-up on a few things this weekend. Unfortunately still trying to find a likely culprit for the coolant leak. I was planning on using some head gasket sealant or replacing the head gasket, but now I'm not so sure?

Compression Test Results
I think results are within range, although 4 seems a bit lower than the rest.

1. 142
2. 135
3. 137
4. 130
5. 135
6. 134

Oil Clear & Coolant Clear

Possible Fouled Spark Plugs
@surfcraft3 Thanks for the tip on checking the spark plugs. I did notice that the new spark plugs (2 months old) seem dirty. Spark plug 1 is clean but the rest were cover in soot and black. (Image shown in reverse order 6-5-4-3-2-1)

I'll try and test for exhaust gas in coolant in the future... but for now kind of trying to figure out what a good next step will be.

 

[OSS]

Maybe it's oozing out somewhere not fast enough to leave drips.
If you could smell it burning, that's a clue it might be an outside leak somewhere.
If coolant was getting in a cylinder, that spark plug would be sparkly clean.

Hmmm #1 looks a wee bit suspicious but the evidence isn't conclusive.

 

[cwwfj60]

@vankho how much coolant are you adding?

smelling coolant can definitely be a leak, especially leaking onto a hot engine Somewhere...

check the engine very deliberately with a good flashlight and a mirror to help poke around the front accessories (water pump/hose area), maybe a small leak. Radiators are common at this age also, check both tanks top and bottom. Heater cores? Could you have a smell from coolant leaking in the cab? This would be passenger floorboard area.

Also white puffs? Could this be early morning steam perhaps? Steam will dissipate quickly vs burning coolant (white) which lingers longer and typically smells sweet.

 

[vankho]

Most noob thing ever.

@cwwfj60 I found myself adding up to the Full line before each drive.

Tonight, I got some UV dye to add to the coolant to help me with spotting any external leaks. I add the UV dye and go for a short drive to get it to operating temperature. I shine the UV light around the engine bay and scour for possible leaks and don't find anything.

I put some coolant on top of the reservoir to see if the UV actually works (it does), then I shine a light inside the reservoir and see that it's perfectly at the full line. Previously, I added coolant to the Full line with a cold engine. All that to say, maybe I don't have a coolant leak? Should coolant in the reservoir be at FULL when cold or hot?

 

[cwwfj60]

Full is typically when warm.

if your engine is completely full (no air) and you fill up your reservoir cold, you’ll most likely lose some due to overflow out of the reservoir cap hose that dumps off to the side.

 

[Gretsch]

All that to say, maybe I don't have a coolant leak? Should coolant in the reservoir be at FULL when cold or hot?

I think its normal for the coolant level to go up or down with the temp of the engine. Coolant expands some when hot versus cold. System is designed to handle this expansion. On mine with the bottle filled to the full line when cold, it goes through a cycle where the coolant in the overflow bottle is above the full when hot and below the full line when cold. The take away is that the bottle is never completely empty or never overflows. Just slight expansion/contraction between hot and cold cycles. It always stays this way after filling to the full line. I stopped worrying about it after a few months of seeing this. Chalked it up to normal heating cooling cycles coupled with evaporation of the coolant.

My experience is that leaks only shows themselves with the system under pressure. With the engine running the combination of movement of air and heat of the engine make coolant leaks dry up long before they can be seen. The UV dye should reveal leaks to you but maybe get a pressure tester kit in combination with the dye and put the system under pressure to see if any leaks reveal themselves. The combination of pressure and dye should allow you to see any visible leaks. If nothing else it could tell you if your system HOLDS pressure or not perhaps indicating an internal leak you cannot see. HTH.