1992 Toyota Camry 5SFE, 246k miles, 6,000 UOA

[Cressida]

This UOA was on a blend of 1 qrt. Supertech 5w-20, 1 qrt. 15w-40 Castrol HDEO and the remaining oil fill was 5w-30 (older API SL or SM). Sorry about this unique "Botique" but I was using up some loose end quarts and hadn't planned on the UOA.

This engine has never overheated or blown coolant out of the expansion tank, however I am finding some very small bubbles coming into the expansion tank. I have to take off the overflow cap to look inside to find them because they are not big, or violent, enough to notice through the partial discolored tank side wall. The bubbles are not always consistent but can show up for a few seconds and then nothing for a few seconds - but they are always to be found if you spend a moment to really look and wait for them.

I did a complete timing belt service 1/2 way through this oil cycle and when I was checking over everything that is when I first noticed the bubbles. That has been 4 months and 3,500 miles ago and never an overheating, overflowing coolant, or engine problem during this time.

The cylinder compression test is even across the cylinders with no visible coolant on spark plugs or in the cylinders. The cooling system is holding 12 psi when pressure tested, and the system was under this pressure when doing the cylinder compression test with no changes noted. I also installed a new Toyota radiator cap and it has made no difference.

Still, I don't think any on-going bubbles appearing in the reserve tank is a good thing

so I did the UOA and below is the report. Note that they are reporting negative for glycol, but we do have Potassium showing up.

Code:




Lab comments:

* Wear Levels Appear Normal.

* Silicon Level is high (Possibly dirt as silica).





Aluminum: 10

Chromium: 2

Iron: 25

Copper: 6

Lead: 15

Tin: 0

Moly: 24

Nickel 1

Silver: 0

Titanium: 0

Boron: 31

Silicon: 36 (I think could be from the Silicone grease I used on all the oil seals replaced)



Sodium: 493 ?

Potassium 19 ?



Calcium: 2904

Magnesium 99

Phosphorus:1119

Zinc: 1263

Barium: 0



cSt Viscosity

@ 100°C: 10.74



Glycol: Negative



Water%)


Oxidation 19.05

Nitration 8.82




Does this all seem to be pointing to a "pin hole" type head gasket leak?

Regardless, I think it is ok to continue driving for now, while watching for any changes, or more definitive symptoms to show up. Do you agree?

 

[SR5]

You have 493 ppm Sodium (Na). Some oils like Valvoline, Napa and Royal Purple use a Na based detergent, but most oils do not (Ca and Mg based).

The Na can point to coolant leak, if you are not using a oil with a Na detergent package. I would use a well know non-sodium oil (eg M1 5W30) for my next OCI and monitor your sodium levels.

 

[53' Stude]

Head gasket. Sodium tells me this

 

[FlyNavyP3]

I think the Super Tech that h out used is a likely contribution to the Na you're seeing. I would continue to keep an eye on it for now if you're not ready to tear into it for a head gasket job right now. Keep an eye on the coolant and check back with another sample at your next OCI.

However with the fine bubbles it's probably when not if it will need a HG. Also you can buy test strips that test for combustion gasses in the coolant which would confirm your suspicions of a leaking head gasket.

 

[53' Stude]

Yeah, the ST oil if it was SM didn't have much sodium. Maybe from the Castrol or....

Either way it needs a head gasket

http://www.pqiamerica.com/SupertechApril2010.htm

 

[FlyNavyP3]

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4146942/Re:_87_4Runner_22RE_ST_Conv_5w#Post4146942

My oil change on ST from earlier this year shows Na in it however not as much. So the ST conventional definitely has sodium as of recently. But I agree on the head gasket.

 

[53' Stude]

Current SN Super Tech oils don't have sodium. Gotta be from previous oils used or....

 

[LBZ_98]

I also have a 1992 5S-FE, but in a Celica.
My coolant also showed small bubbles but it doesn't really point to a HG leak even though the coolant was absolutely disgusting when I flushed it. Recently I was worried that it really was a HG leak since when I'd start it up, there would be the mayo/peanut butter under the oil fill cap, but after driving it more frequently (it was sitting as the season transitioned from summer to fall) I realized the mayo/pb was probably from condensation as a result of the weather changing. Engine is running strong.

Now I did do a UOA when I first got it 6 months ago, (but I didn't know what oil it from the previous owner) and the UOA revealed 166 ppm of sodium, but Blackstone noted the oil may have been a Mobil Super product since it also had 24 ppm of titanium. Both elements are part of a Mobil Super additive package according to them.

 

[Cressida]

Update: Here is my latest UOA with about 5,000 miles on this oil run of Rotella T5 10W/30. (There was another oil change later in 2017 that I didn't do a UOA).

Since I still see the bubbles appearing in the coolant reserve that I mentioned in the OP to start this thread, I was looking for evidence of coolant in the oil. The lab reports Negative.

So nothing negative appears to have changed. This engine continues to run fine, never overheating or pushing out coolant. Nevertheless as mentioned, the bubbles continue to be present when looking in the coolant reserve tank. This UOA below is actually one of the best I've experienced so will continue to do nothing until more symptoms develop, or the evidence tells me otherwise.

Code:


Lab comments:

* Wear + Contamination Levels Appear Normal. No corrective Action is needed.

* Change to Rotella T5 10w/30 noted.

* Negative Antifreeze Detected. (Some had been suggesting that head gasket was bad so I told them I was watching

for any signs of coolant in the oil)



Aluminum: 6

Chromium: 1

Iron: 11

Copper: 5

Lead: 1

Tin: 0

Moly: 47

Nickel 0

Silver: 0

Titanium: 0

Boron: 44

Silicon: 5 - surprised how low this was as I had the valve cover off during this run



Sodium: 208 - trending down, perhaps some residual left from the past

Potassium 4 - same as VOA level



Calcium: 1967

Magnesium 99

Phosphor: 1099

Zinc: 1546 ? Don't know why because this is higher than the VOA for Rotella T5

Barium: 0



cSt Viscosity

@ 100°C: 11.04



Glycol: Negative



Water%)


Oxidation 17.48

Nitration 2.25

 

[bbhero]

Good deal.

High potassium and sodium would be very telling if you had coolant in the oil. High Na+ does not necessarily mean a head gasket leak. Again having high k+ and high Na+ would mean trouble. Potassium at 4 here is a very positive sign indeed.