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My 1992 Dodge Grand Caravan 3.3L suddenly started ticking which appears to be near the top side. The ticking rate follows the RPM. Then engine seems to be performing fine. No noticeable power loss or other effects.
Issue 2 (possibly a cause): For a good year or so I have notice the oil filler cap getting rusty on the inside surface. I’m assuming this is moisture related. Possibly coolant, but the oil itself appears to be fine so if it’s coolant it’s not much. The fact that it only seems to collect on the cap seems to indicate it is vapor collecting there? The rubber is fairly hard so maybe it’s not sealing well and cold MN air is getting in and condensing?
Is there anything besides coolant that could cause a moisture build up in the valve cover area?
Any suggestions on what I should look at first? I am thinking about taking the valve covers off and just doing a visual inspection to start with.Additional notes: This van has 420,000 miles. I decided to keep driving it until something major dies, and this may be it, but if I can fix it in a few hours, I will.
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Yes. Moisture itself. Not trying to be smart, by product of combustion is water, only in steam form and very little. Being a gas, it blows by piston rings and eventually condensates in crankcase.
Wonder you not though. You have coolant mixed with water. This is infamous milkshake. Now you have to do all kinds of fancy tests to find out what and where.
Coolant mixed with oil. Can’t type. Old.I would run two tests on your engine. First would be a cooling system pressure test(which I believe would be failed by your car) and a compression test to check the rings. You have cross contamination, possibly a head gasket issue, which both tests can verify. Hope it’s only a headgasket, it could be a cracked head or block.
Additionally, if you look carefully with a good flashlight as you drop the oil from the oil pan, you should see a separate small milkshake stream within the dropping stream of oil. Drop it while engine is cold/ has been sitting a while. The reason being is that oil and water tend to separate. If the milkshake has already clouded oil at the dipstick though, this simple test won’t really confirm anything. I agree with ukrkoz, looks like the bad milkshake to me.
Built back then makes me think that that is a Mitsubishi engine. That mileage is crazy.
Anyway, an engine with that mileage is going to have more than the normal amount of blowby. As ukrkoz already wrote, one of the products of combustion is water. So, the source very likely is combustion. Living in Minnesota this time of year means the water will condense in the valve covers. If fluids are not disappearing at more than a normal rate I suggest replacing the PCV valve. The noise may be a separate issue.
Thanks for the ideas. I will replace the PCV valve as it is cheap, easy, has been a long time since I replaced it and now I know what it does. I do agree that it may be just vapor since the oil and coolant look normal.
As for the ticking sound I think I will use the stethoscope to try to narrow down the area and maybe pull of the valve covers and take a look.
I will report back with my findings.
Barnyb Yes, I believe it is a Mitsubishi. I have a 1997 and 1998 caravan also with the same engine. The 1997 is a 3.8 liter version though.
Under certain conditions the caramel on the oil cap is normal. If you do very short trips in cold weather the engine doesn’t reach operating temperature long enough to boil the moisture out of the oil so it collects on the cap.
An engine that has a failed thermostat or a plugged PCV valve can also have this problem.
As for the ticking, that engine had problems with soft camshaft bearings that turned in the block and blocked oil flow to the heads. It also had problems with the cylinder head mountings for the rocker arm shafts cracking and breaking.
Ticking issue Resolved!
Can you see the rocker arm that doesn’t fit in with the rest?
The far left rocker has a hole.
By ear it sounded like the noise was more likely in the rear valve cover, but I also listened with a stethoscope. Pressing it against the valve cover bolts The ticking seemed loudest at the bolt in front of the oil fill cap. I wasn’t sure if this was the same ticking I was hearing without the stethoscope though.
After pulling the valve cover off, it became obvious there was at least one issue discovered.
The rocker with the hole was right below the oil cap. I could see it without taking the valve cover off, but I assumed the hole was supposed to be there until I saw the rest.
Some of the other rockers had significant wear also, but at most maybe 1/4 to 1/3 of the way through.(Does anyone know if the outer wear surface is hardened or is it the same all the way through?)
Here are the new parts installed:
The ticking sound is now gone. I imagine there would be similar wear on the other 6 rocker arms, but they are more difficult to get to and I plan to leave them as is for the winter.
I also replaced the pcv valve and will have to see if it reduces the moisture issue.
My brother-in-law was a fan of Chrysler minivans back when they had Mitsubishi engines. When new these engines developed so much oil pressure the pressure would deform the oil filter can and the filter would unscrew. He and his family lived 150 miles away and they often came to stay with us and oil up my driveway. Every time they arrived I reached under to screw the oil filter back on. That engine had to have experienced low oil on more than a few occasions. He never had engine problems. Tough engine.
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