The Stupid Engine Questions Thread

[jcaobjim455]

Hello all, first time posting and this seems like the perfect spot!

I've got a '90 c2500 Scottsdale with the 5.7L small block, and I'm pretty sure I have the 20" radiator w/o an engine oil cooler. Pic for reference. I've been looking for a shroud for this thing, but everything I find online seems to be for the 28" radiator. Where do I find a shroud for this tiny thing, or what's the part number from GM? Previous owner left the broken bottom like that and didn't replace it at all, seemingly for the same reason I just ran into.

For reference, this is my first time owning a truck. Maintenance seems pretty easy with the Haynes manual in hand. I have no clue how a little box radiator like that keeps this thing cool, especially without the shroud, but its kept cool so far just commuting with it.

Edit to mention I accidentally bought some shrouds for a 28" radiator without doing proper research. If I can't find a reasonable replacement within the return limit I may just keep them, and throw more money at a larger radiator too. If I do, does that mean I have to replace the fan blades as well?

 

[RanchWelder]

I Have a 98 Silverado 5.7 CSFI with a rough idle, it was popping the P1345 code and I replaced plugs, wires, cam sensor, cap, and Rotor.

My scan tool is showing a cyl #1 timing offset of around 20deg, which jumps around a bit but hangs around there. the previous rotor and cap nearly fell apart when I took them off, previous wires had electrical tape on them (like that's gonna fix it) and the plugs were rusted (and red/orange!?). clearly needed servicing but im not sure which direction to go, I advanced the timing by one tooth and it ran way worse so I put it back. should I look into the ignition coil? should I look into fuel delivery or the timing chain? which direction should I go?

Start with either a new or properly rebuilt Davis Unified OEM distributor... ACDelco or GM coil, connectors, bushings, cam gear, ignition module etc... Unless you confirm the Distributor is 100% solid, you can chase your tail on this forum with wild answers and a lot of swapped parts.

Timing is everything.
Broken magnets, bad wiring under the cap, worn cam gear, is usually a sign of a damaged distributor.
When you pull it out, is the bottom covered with a thick layer of baked on grease?
If so, it's baked inside the shaft as well. Good cleaning might work?
PB Blaster and some rubber gloves?

Most can be rebuilt not all. Coil wear is common. Baked wires under the flying magnet case cover...

The cheapo distributor units will let you down 100 miles from home... There is no short cuts with ignition components. You absolutely get what you pay for with every part.

 

[Orpedcrow]

97 c1500 5.7 vortec L31
I either need part numbers or some verification of fitment for both the harmonic balancer/crank bolt and flexplate bolts, Napa and Summit show fitment for “small block Chevy” but nothing for my 97 c1500 5.7 vortec. Machine shop chucked mine in the scrap bin and shrugged their shoulders at me. Is a Sbc is a Sbc is a Sbc? Or is the vortec crank different?

 

[Rickf]

The previous owner put a 180* thermostat in my 1990 sierra 1/2 ton, will the 5.7 explode? Should I put a 195* t-stat in?

 

[FourEightZero]

I'm looking for iridium plugs to replace the ACDelco R44LTS plugs I've been using.
(TBI short block, 906 Vortec heads)

Suggestions?

 

[Orpedcrow]

I'm looking for iridium plugs to replace the ACDelco R44LTS plugs I've been using.

Suggestions?

I’ve never experienced a failure from NGK plugs. I think they make some of the acdelcos now anyway. I just bought these for my rebuilt engine

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[93chevyluvr]

I was suggested by someone to use ez out to remove my broken manifold bolts. Is it reliable? Because the shops around me don’t service exhaust manifolds and I figure it would be cheaper it I just replaced them myself.

 

[BIGBLOCK92]

Alright. I am having issues with my 7.4, its carbureted and once its warm it wants to die at lights, and then diesel when I go to turn it off. I turned the idle down a half turn and the air screws down a 1/4 on each side and it helped, it doesnt die at a stop, but now it died in reverse backing into my drive way...I have not checked with a vacuum gauge yet, that is my next step. and then pulling the plugs and checking the timing. Anything else you all can think of?

 

[Fragment]

Here's my stupid question...

In this video here: Youtube

Is the noise on the passenger head a valve adjustment issue, or an exhaust leak in your opinion?
Drivers head is shown first for comparison.


Thanks!

 

[GrimsterGMC]

Here's my stupid question...

In this video here: Youtube

Is the noise on the passenger head a valve adjustment issue, or an exhaust leak in your opinion?
Drivers head is shown first for comparison.


Thanks!

Definitely valve train.