Intermix questions

[dammad]

My '99 C2 Cab appears to have developed an intermix problem. I was driving home yesterday and the low coolant light came on. I stopped and checked, coolant was low but I couldn't get the coolant tank top off for a top up even after letting it cool a bit. Since it was pouring and near to home, I drove home and checked it this morning. The coolant appears to have a thin (couple of mm think) layer of mayo/pancake batter. I checked the oil dipstick and the oil looks normal with no 'chocolate milk'. 

 

As a long time poster/lurker, I've read all the threads on intermix and fear I've perhaps a oil cooler problem (oil in coolant but nothing obvious in the oil). However, the coolant level is way down now so must have gone somewhere. I plan on flat bedding it to a local independent but with the holidays it might be after the holidays when they reopen. Is there anything I can useful check myself beforehand? Cylinder pressure test? Dump the oil and look for water? Or should I just wait?

Edited December 20, 2014 by dammad

[JFP in PA]

My '99 C2 Cab appears to have developed an intermix problem. I was driving home yesterday and the low coolant light came on. I stopped and checked, coolant was low but I couldn't get the coolant tank top off for a top up even after letting it cool a bit. Since it was pouring I drove home and checked it this morning. The coolant appears to have a thin (couple of mm think) layer of mayo/pancake batter. I checked the oil dipstick and the oil looks normal with no 'chocolate milk'. 

 

As a long time poster/lurker, I've read all the threads on intermix and fear I've perhaps a oil cooler problem (oil in coolant but nothing obvious in the oil). However, the coolant level is way down now so must have gone somewhere. I plan on flat bedding it to a local independent but with the holidays it might be after the holidays when they reopen. Is there anything I can useful check myself beforehand? Cylinder pressure test? Dump the oil and look for water? Or should I just wait?

 

First thing, stop running or using the car.  If you have access to a cylinder leak down tester, that would be a good place to start.  A compression tester may also give you some data, but a leak down would be preferable.

 

I would also pull the filter and look at the oil in the canister for signs of coolant.  If you have coolant in the oil, DO NOT run the engine further.  Coolant is Hell on bearings and machined surfaces.

 

While the oil cooler can be the source of intermix issues, by far, most result from cracked cylinder heads.

[Kim]

http://www.flat6innovations.com/index.php/services/intermixed-oil-and-coolant-repairs

Having just been through this ... with a cracked head as the cause, I suggest you read this link to gain further understanding:

 

 

 

[san rensho]

you can also try removing the spark plugs, pressurizing the cooling system and listening in the spark plug holes with a piece of flecible tubing for the telltale hissing of escaping coolant.

[dammad]

Many thanks for all the feedback. Alas with the holiday build up I didn't get time to do a leak down test. I'll take it to my local shop for just a leak down test in the new year, unless it is easy to get the  engine to TDC.

 

Happy Holidays to everyone!

[Domiac]

I'll take it to my local shop for just a leak down test in the new year, unless it is easy to get the  engine to TDC.

 

If you perform leak down test by yourself, have a look at http://www.renntech.org/forums/uploads/monthly_04_2014/post-93239-0-35664900-1397384617.png which helps you to find out TDC compression cycle for each cylinder.

 

Here are the steps

1. Turn crank into TDC Zyl #1 mark, now test Cyl #4

2. Turn crank 120 degrees, now test Cyl #3

3. Turn crank 120 degrees, now test Cyl #5

4. Turn crank 120 degrees, now test Cyl #1

5. Turn crank 120 degrees, now test Cyl #6

6. Turn crank 120 degrees, now test Cyl #2

 

A few tips about this test:

- on 996's turn crank only clockwise

- Zyl #1 mark on crank means TDC overlap for cylinder #1 and TDC compression for cylinder #4

- a proper tool to find out the exact TDC point helps big time

- let someone (or you) hold crank in place while pressurizing, otherwise engine might turn if you are off from TDC

 

Please post your or the shops findings here.

[dammad]

After a very busy beginning of the year, I got the car looked at last week. The shop (Don's Autowerks) reports that I've low compression on *all* cylinders. Starting from Cylinder #1-6: 155, 155, 150, 175, 170, 165, when it should be 210+. While the head might be cracked, but I would have thought it would only effect 1 or 2 cylinders. Does anyone have any ideas?

 

I'm west coast based, so LN Engineering is a long way away. Does anyone know of a shop on the West coast that fixes these? Or a source for cheap engine replacements?

[rbrindley1]

On the west coast suggest checking out CallasRennsport. Tony Callas and Jake Raby have done a lot work together over the years. Good luck!!

[dammad]

Thanks! Has anyone heard of low compression on all cylinders?!? Seems very strange to me given the car ran fine up to the intermix.

[JFP in PA]

Thanks! Has anyone heard of low compression on all cylinders?!? Seems very strange to me given the car ran fine up to the intermix.

 

Only on engines with very high mileage or scored cylinder walls.

[dammad]

Mine has 156k miles, but I've been changing the oil regularly with Mobil1 0w30 so believe wear should be a minimum. Don't believe I've any scoring, but will have them look into one of the cylinders for more information.

[JFP in PA]

Mine has 156k miles, but I've been changing the oil regularly with Mobil1 0w30 so believe wear should be a minimum. Don't believe I've any scoring, but will have them look into one of the cylinders for more information.

 

Have you really been using 0W-30 oil?

[dammad]

Oops. Meant 0w40. Sorry, long day at work.

[Kim]

 

I'm west coast based, so LN Engineering is a long way away. Does anyone know of a shop on the West coast that fixes these? Or a source for cheap engine replacements?

 

When I was picking up my car at Jake Raby's shop last fall, they were putting a California car in a truck to ship back to a west coast customer.