Latest oil change/ oil filters

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Larryjb

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I've been doing oil changes on my own vehicles for 30 years now, and just experienced something that disturbed me a little.

I've been using Wix filters now for 15 or 20 years, and as far as I know, they're great filters. On my Tahoe, I noticed that the oil pressure dropped earlier this spring. After I did an oil change I noticed a lot of sludge in the oil after switching to Valvoline synthetic. After changing the oil/filter, the oil pressure returned to normal. A couple of months later, before the next oil change was due, I noticed the oil pressure dropping again. I changed the oil filter again, and the oil pressure returned to normal, once again. Only this time, I didn't have access to a Wix, so I had to use another brand. This time I wasn't losing any oil pressure, or very little, even when it was time to change my oil again this month. When I removed the drain plug, the oil wouldn't even come out right away, and came out in globs! It was all sludged up, but I wasn't losing oil pressure.

I figure that the Wix does not have a bypass valve, so when the filter gets plugged up with sludged oil, the pressure drops giving you warning that something needs attention ASAP. This other brand of filter had a bypass valve and allowed the sludge to pass straight through, all over my valve train and everything.

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I had never thought of the cons to having a bypass valve until today. I will now always keep a stock of a few Wix filters (or ACDelco, or other decent brand that does not have a bypass filter). If I see the pressure dropping, I know to change the oil pronto, even if the usual oil change interval has not yet passed.
 

08grey

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Run some kreen through your motor before your next oil change.

Sent from my SM-G950U using Tapatalk
 

Z15

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Sludge is not normal, something is wrong. Could be a coolant leaking (head gasket?) into the oil that is causing it to form sludge. Start saving money for a new engine.

You want filter with a bypass valve, without one and the filters get clogged, the engine is starved of oil and will self-destruct.

Where year is the Tahoe? Early 5.3L engines had bad heads, defects in production.


Ps - I know of no oil filters for GM vehicles that DO NOT have a by-pass valve in them.

EAO_ExplodedFilter_900px.jpg
 
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Larryjb

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I put the coolant pressure tester on Friday evening and it's slowly dropping. It lost about 5-7 lbs overnight. A little of that would have been from the engine cooling, but it had already cooled a couple of hours before putting the tester on. Unfortunately it has been raining tons here, but I cannot see any sign of coolant leaking from the engine area. I haven't yet checked the rear heater core and connections. This could be another possibility for a coolant leak.

I had been pulling a 3500 lb trailer last October, and before that I had pulled the trailer up to Kamloops and back. This involved some pretty steep grades. I should have changed the oil right after the trip, but I just didn't have time. I did change the oil filter, though. Because I seemed to have good oil pressure, I thought I was okay.
 

Z15

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I could be intake gaskets, the RTV sealant failing.
Problem Description
The intake manifold gasket may develop an external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Our technicians tell us that operating the engine with a coolant/oil mix can result in internal engine damage. Replacing the intake manifold gasket should correct these leaks.

(127 people reported this problem)

I recommend you have the oil tested, here is a postage paid kit you can purchase and mail in an oil sample. When you buy this kit, it includes shipping and the test, so no money has to be sent in with the sample.

Oil Analyzers Test Kit, Postage Pre-Paid
 
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Larryjb

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an oil test kit has been ordered.

If I recall correctly, this 5.3 L has no coolant in the intake. I replaced the IM gasket last winter.

I wonder if the trip pulling a trailer up the Coquihalla damaged the
head gasket or head? Temperatures did rise a little (up to 115 C). I kept the RPMS near 4000 though.
 
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Larryjb

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It's a 2002.
My oil pressure was dropping to around 25 or 30 psi this week again so I changed the oil and filter. The oil was fine and not sludged, but the filter was getting plugged a little. After the oil change it was back up to 40 at idle.

From what I'm reading, the oil bypass is built into the oil filter adapter, so the filter does not need the bypass. The filter I was using before may not have been filtering as effectively as the Wix or the ACDelco, so did not get plugged as easily. I cannot remember what brand I used last year, but it wasn't a Fram label.
 

Z15

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Are you using the correct viscosity oil, e.g. 5W-30? Are you using a name brand oil?
 
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