Head gasket question 2007 4runner V6 - Toyota 4Runner Forum

Drcoffee · 10-03-2020, 08:33 PM

Im a little confused with my 07 4runner V6. I have just bought a truck with 222,000 miles. I found a leaking radiator and water pump. I have replaced them. When I start the engine, there seems to be more steam than normal, they it fades, then normal amount of vapor coming out until warmed up. I also see some white ash in the tail pipe. And #6 spark plug looks like it has a little residue that the others dont. So I assume my #6 head gasket has a small leak. There is no rough idle or CELs as others report. It runs strong. The coolant resevior never gets pressurized and never too much coolant in it, right at the hot level. But I cant tell if Im losing coolant because its getting colder lately, but its never empty, not yet.

Is it possible to burn coolant in #6 but not get pressure in the cooling system? If its leaking into the cylinder on cool down, it must be pressurizing the cooling system when running. Am I right?

I dont know if this has any importance, but my long term fuel trim is 0% B1 and 7.8% B2. Down stream O2 sensors seem to be slow so I will replace them soon. I wonder if a coolant leak on B2 has damaged the up stream O2 sensor.

Im tempted to add some Bars head gasket sealer, but not if its not a head gasket issue.

Any help from those with prior experience would be appreciated.

ecally · 10-04-2020, 10:10 AM

Did you replace the radiator cap also?

Drcoffee · 10-04-2020, 10:26 AM

Quote:

Originally Posted by ecally

Did you replace the radiator cap also?

No, I didnt. It seems to function correctly.

AuSeeker · 10-04-2020, 12:10 PM

Your post doesn't say, so it's not clear to me that you're losing coolant, I wouldn't do anything until you see clear symptoms of head gasket failure, your 2007 V6 T4R was built after Toyota redesigned the head gaskets which was 12/05 and I haven't seen any 2007 V6s reporting head gasket failure.

firebirdguy · 10-04-2020, 12:54 PM

Quote:

Originally Posted by AuSeeker

Your post doesn't say, so it's not clear to me that you're losing coolant, I wouldn't do anything until you see clear symptoms of of head gasket failure, your 2007 V6 T4R was built after Toyota redesigned the head gaskets which was 12/05 and I haven't seen any 2007 V6s reporting head gasket failure.

agreed, dont add sealer or worry too much until there are definite tell tale signs of a bad h/g. 2007 should not have the issues earlier models had.

Drcoffee · 10-04-2020, 10:41 PM

Im not blowing coolant out the resevior so I will continue to drive it and monitor it. Its not my primary vehicle but I will come back with updates. Thanks for your input.

Captsolo · 10-06-2020, 09:16 AM

I think your HG is going. Use the HG tester you can buy online for $30. If it turns from blue to yellow slowly, it's the HG. Watch Scotty Kilmer Youtubes for HGs.

Scotty Kilmer Youtubes for head gasket - Bing video

Scotty Kilmer Youtubes for head gasket - Bing video

Drcoffee · 10-06-2020, 04:38 PM

I have noticed white residue in my tail pipe. Thats a good idea to test the coolant before throwing any more money at it.

I can hear a high pitch whistle coming from the drivers side intake. I think I may have a vacuum leak either at a fuel injector or plenum gasket. Once I find out about the head gasket, I will tackle the vacuum leak.

simple · 10-07-2020, 03:14 AM

Try getting an oil analysis done smith blackstone labs. They’ll be able to tell you if there’s coolant in the oil

Drcoffee · 10-07-2020, 08:20 AM

Quote:

Originally Posted by simple

Try getting an oil analysis done smith blackstone labs. They’ll be able to tell you if there’s coolant in the oil

Thats not a bad idea. I have checked the oil and it looks clear and no froth/foam so far.

simple · 10-07-2020, 11:13 AM

Quote:

Originally Posted by Drcoffee

Thats not a bad idea. I have checked the oil and it looks clear and no froth/foam so far.

On one of my oil analyses I did they found a high concentration of potassium which lead them to believe it was coolant in the oil and I may have a HG leak. It was right after I had my water pump changed. I don’t know why or how coolant got into the oil, but I have a 08 so HG isn’t common. I changed the oil again and got it checked and there was still a trace amount but much left. They said if I did the repair, it may just be a little residual. One more oil change after that and my numbers were normal. It’s 30 bucks or so. Not worth every change, but certainly good piece of mind every now and then. Especially if you’re worried about a HG leak. The compression test with the blue fluid is not super accurate. The liquid may slightly change shade and you’ll run yourself crazy on whether or not it’s positive.

Drcoffee · 10-07-2020, 11:25 AM

If the test is slightly positive, using a bars sealer might just stop it from progressing vs waiting until it is too large to plug.
There shouldnt be any coolant in the oil.

y=mx+b · 10-07-2020, 11:47 AM

Quote:

Originally Posted by simple

On one of my oil analyses I did they found a high concentration of potassium which lead them to believe it was coolant in the oil and I may have a HG leak. It was right after I had my water pump changed. I don’t know why or how coolant got into the oil, but I have a 08 so HG isn’t common. I changed the oil again and got it checked and there was still a trace amount but much left. They said if I did the repair, it may just be a little residual. One more oil change after that and my numbers were normal. It’s 30 bucks or so. Not worth every change, but certainly good piece of mind every now and then. Especially if you’re worried about a HG leak. The compression test with the blue fluid is not super accurate. The liquid may slightly change shade and you’ll run yourself crazy on whether or not it’s positive.

05 v6 210k miles at analysis, I had 50ppm potassium in my last oil analysis with some sodium (maybe 20ppm?) as well. The numbers are actually coming down compared to previous analyses, which is odd. I haven't done anything water pump, so I think its slight HG leak. Blackstone actually thought I fixed it based on the numbers, but I haven't done anything lol. What did your numbers look like?

Drcoffee · 10-09-2020, 03:04 PM

Well this is good news. The test was negative for head gasket leaks. The fluid stayed blue after about 5 minutes of bubbling

I bought the test kit so I will periodically recheck the engine. Im still wondering why I get white residue in the exhaust though.

Next step is to find out why I have a lean condition on Bank 2 drivers side. Maybe just needs new plenum gaskets and fuel injectors.

djpope09 · 10-09-2020, 04:24 PM

Quote:

Originally Posted by Drcoffee

Well this is good news. The test was negative for head gasket leaks. The fluid stayed blue after about 5 minutes of bubbling

I bought the test kit so I will periodically recheck the engine. Im still wondering why I get white residue in the exhaust though.

Next step is to find out why I have a lean condition on Bank 2 drivers side. Maybe just needs new plenum gaskets and fuel injectors.

That test kit looks awesome. How lean is your bank 2? I've noticed that my LTFT on that bank is around 10% while the other bank is closer to 0%. I haven't been able to figure out why. I don't have a whistle like yours, but I also haven't tried to track down any vacuum leaks. I'm interested to hear what you find.

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