95 Blazer running terribly, engine noisy

Well my Blazer is going downhill FAST. This weekend I put on a new EgR hoping that would fix the problem of poor acceleration and knocking. Well it didnt. But with it plugged in the acceleration was MUCH worse. So I unplugged it, and the knocking got worse but the acceleration got better.

Well the knocking has gotten worse every day. Now its wednesday and its horrible and loud I wonder if my exhaust system is coming aloose or something. I plugged the EGR back in and no real change. Now there sounds like knocking, rattling, some squeeling, all in tune with the RPMs it seems.

I am convinced that my oil pressure is oddly low as well. and when at idle it drops into the red and engine light comes on. But the oil level is fine. The pressure does go up when the engine RPMs.

All this shit seemed to start after I had the oil changed and the radiator flushed.

You think they screwed something up, maybe somehow my filter is bad or too small, or can the oil pump be broken or something? I hope im not burning up my engine but I have a sinking suspecion that I am.

Any ideas?

Reply to
CL (dnoyeB) Gilbert
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I should add that the situation has become considerably worse after I put premium gas in it just yesterday.

Reply to
CL (dnoyeB) Gilbert

You could easily be describing an engine with a spun crank bearing.....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: N>
Reply to
Mike Romain

How bad is that in dollars?

Thanks,

CL

Mike Roma> You could easily be describing an engine with a spun crank bearing..... >

Reply to
CL (dnoyeB) Gilbert

You can sometimes get away with opening it up and replacing the one bearing, but if one spun, the rest are usually worn out too. That normally involves a remanned crank and bearings. Then if you are going to replace the bottom end, how bad are the rings and valves? A compression test and leakdown test will tell you about the top end, it might be fine still.

Usually it is best to just get a rebuilt shortblock and put your parts back on it if the rest is still decent.

Mike

"CL (dnoyeB) Gilbert" wrote:

Reply to
Mike Romain

"CL (dnoyeB) Gilbert"

You need to find out exactly what the problem is, CL. Don't throw parts at this. Yes, you may have a bearing problem, but it could as easily be something else.

I am thinking valve train. Chains, tensioners, gears, etc.

Running a few tests is a lot cheaper than throwing parts at this car.

(1) Compression and leakdown will eliminate or indicate some things.

(2) A worn chain or gear or tensioner, if it applies to your engine, may take a little more work.

If you have an internal problem like a bearing,etc, you will have to do deeper surgery.

Reply to
<HLS

I had a guy come in once and grind the crank journal in the car. The bearing was cheap.

Definitely a bandaid fix, but it worked.

There was never a good war, nor a bad piece.

Reply to
<HLS

No surprise, given the stinkin' quality of "advice" you dispense to others.

Take a close look, folks...this is how an individual with an EE degree goes about diagnosing a vehicle: By replacing and unplugging parts at random. Unless, of course, he was lying about the degree.

Open the door and let in whoever's standing out there on the patio.

also known as Wednesday

Ayup, ayour exhaust asystem acould be acoming aloose.

Why not try unplugging...ummmm...the alternator next? And the O2 sensor!

Well, gee, I can't figure out why I ever doubted you. That *certainly* sounds like EGR trouble, you betchya.

So, when during your EE courses did they teach you that the oil pressure light and gauge indicate the engine oil level?

I do: They accepted the likes of you as a customer.

...says the engineer...

Yep!

Reply to
Daniel J. Stern

...asks the engineer...

Reply to
Daniel J. Stern

"Well my Blazer is going downhill FAST. This weekend I put on a new EgR hoping that would fix the problem of poor acceleration and knocking. Well it didnt. But with it plugged in the acceleration was MUCH worse. So I unplugged it, and the knocking got worse but the acceleration got better. "

First questions: How many miles on the vehicle? Has it been overheated recently?

The EGR system is designed to pass a calibrated amount of burned exhaust gas back into the intake manifold to be burned with the incoming air/fuel charge. The main benefit of this is a lowering of the combustion chamber temperature. A non-functional EGR system will make your engine more prone to overheating, detonation and pre-ignition. You will also probably fail an emission test for exceeding nitrogen oxide limits.

Having said that, just replacing the EGR valve will not always fix a problem with the EGR system. Many times the EGR passage is already clogged by the time the valve gives up, leaving you with another problem that is best fixed by pulling the intake manifold and clearing the passage.

It is possible you have burned up a bearing. It's also possible you didn't install the EGR valve correctly and you now have a nice exhaust leak under the hood, which can sound a lot like a bad bearing.

One way to test main bearings is to put the car in drive(automatic) or

4th/5th gear(manual), hold the brakes, and apply a SMALL amount of throttle/clutch to raise the engine RPM and put LOAD on the engine.. Raise the speed about 200 rpm at the most. A knock that becomes progressively louder(to a point) would suggest that you have one or more bad main bearings. Of course if you have an exhaust leak all bets are off. How to tell you ask? Start the engine when it is stone cold first thing in the morning. Start passing your hand near the manifolds, the connections to the downpipe, and the egr valve. If you feel any pulses you just found a leak. Look for a black streak near exhaust connections, the presence of any would likely indicate gas is escaping at that point.

It's also possible the EGR valve is leaking when it opens, and it is not supposed to be open at idle. On the newer GM computer controlled EGR valves(the $300 ones...) I don't know how to force it open to test it. The old style, you use a hand vaccum pump. You will need to have a helper open the throttle slightly, if you open the EGR at idle it will stall the engine. What you want to look for is abnormal noises when the valve opens indicating that the exhaust is leaking OUT of the valve instead of getting sucked into the intake manifold.

I am assuming you did not do your oil change and radiator flush. I hate to say it, but I've never had a positive experience with a mechanic. Ever. They always manage to fix one things and break two others. I would suggest replacing the oil filter immediately if you choose to do nothing else. Cut the old filter open and inspect the filter element. If it is full of metal shavings you just confirmed your suspicion about 'burning up your engine".

Good luck with it,

Chris

Reply to
halatos2000

I design cars, I don't fix em \o/

Reply to
CL (dnoyeB) Gilbert

about 130,000. Overheated only slightly once. Well actually i saw it on the gauge and got some antifreeze in it and it was all right. It didnt fully overheat I suppose since I didnt loost power.

But its leaking antifreeze and the temp gauge goes up and down. Someone said it may be hotter if an airpocket was over the temp sensor...

Yea, in fact this summer the dealership bilked me for about $500 for cleaning the manifold of carbon deposits, so they said. Which would have been OK if they had replaced the EGR valve at the same time, which they did not...Its had a small tap for about a month which i thought as due to needing an EGR due to my experience this summer. So I put EGR on it, but it just got progressively worse over the month.

Yea, I thought about that since the noise is pretty darn loud. But its kind of hard to install it wrong. Just a gasket and two screws. Though I don't know the torque setting. GM did create the think unkeyed so it can install in two directions, but from all my checking its correct.

Yes, I have one of those electronic ones. At this point car runs same with it on as with it off. Im thinking its not the EGR anymore. Its really over my head and im takin it to the shop...

Ok, thanks for the info. My regular mechanic was expanding his shop so i ended up using various other mechanics over these few months :(

Reply to
CL (dnoyeB) Gilbert

Right, sure, you design cars. Which explains why you have no clue how they work.

Reply to
Daniel J. Stern

the EGR on my 95 got caked up pretty heavily where the valve attaches including the valve itself.

The fuel distribution under the plenum might also be leaking by now and is worth looking at or you could have vacuum leak there. If you open it take care in dong so.

Seems with your oil pressure issue, you have bigger troubles now.

Loved my 95, totalled it twice as a matter of fact :)

good luck.

Reply to
ed

Fare ye well old Blazer. We went through a lot together. Can't say i'll miss you though I will miss those brand new tires :(

Engine is shot. I suspect those bozos put a bad oil filter on, but my memory is not sharp enough to recall if the problems started before or after my trip to the EZ-Lube...

Reply to
CL (dnoyeB) Gilbert

"Fare ye well old Blazer. We went through a lot together. Can't say i'll miss you though I will miss those brand new tires :(

Engine is shot. I suspect those bozos put a bad oil filter on, but my memory is not sharp enough to recall if the problems started before or after my trip to the EZ-Lube... "

One option still available to you is to obtain a used engine from a local wrecking yard and have a competent shop install it for you(if you lack the tools to do the job yourself). It would be a lot cheaper in the long run to spend $800-900 on a used engine and $500-600 in labor to have it installed than to start paying $300 a month for the next 5 years to drive a newer car.

I'm of the mentality to maintain rather than replace when possible. If the body is straight , interior okay, and the transmission was functioning normally when the engine went, I would say fix it and keep driving it.

Chris

Reply to
halatos2000

i feel the same way. Its reached that point in its life where its becoming needy. The point where the monthly output is approaching a car note. I have a buddy that can buy and drop an engine in it for me.

I just spent $700 having the fuel line fixed and the intake manifold cleaned this summer. The coolant system is leaking. rear wiper is broken, driver door lock is flaky. transmission fluid had what looked like dirt particles in it. etc. etc.

It *looks* good from the outside. I could probably sell it if it was not for the engine. But it was never a good truck to begin with. OBD1 was a joke. 95 was bad year for a blazer unfortunately.

This is my first GM to die like this. My 84 caprice classic station wagon was running like a top when I sold it in about 95. This was unfortunately considerably worse than my 84 experience.

Reply to
CL (dnoyeB) Gilbert

where ya throwing it away at?

Reply to
ed

Charity Motors or some similar place I can get a tax writeoff from.

Reply to
CL (dnoyeB) Gilbert

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