Radiator or headers?

**Hhammer15** · 05-24-2011, 06:26 PM

So here is the deal: I am a beginner mechanic and broke so before I go replacing stuff I need to make sure it I am making the right decision. Idk the best way to list all of this so I'm going with bullet form:

Issue:
Car overheating

Replaced:
thermostat, and coolant sensor (I think, it's the one on the driver side toward the front of the block) and the alternator went out last week so I replaced that too (idk if that is relevant but w/e)

Symptoms
reading overheating to the point that fluid boils out. I have a crack in the radiator but it still shouldn't do that. The one owner that had it before me used that dexicool crap that Chevi makes and I think that is clogging stuff up or corrosion. the coolant looks like it is kicking up sludge in the bottom of my resevor. I would go with replacing the water pump but it is pumping though fine some day's and the previous owner replaced it 3 years ago. took it to the mechanic and his diagnosis was blown headers but it isn't smoking or anything. There is a slight slight clicking noise though which concerns be but I am pretty sure I just need to replace the radiator.

Just need an expert opinion on who is right. and if it is the radiator I will deff need a step by step to replace it. have the tools but no prior knowledge and am broke and determined enough to do it myself.

Thanks,

William

**KMdef9** · 05-25-2011, 08:49 AM

What color is your exhaust?

**KMdef9** · 05-25-2011, 08:51 AM

An on a second thought, if you want to def. rule out blown head gaskets, you can get a compression test done.

**JayTA98** · 05-25-2011, 09:18 AM

are your engine fans turning on? how did you confirm that the water pump is working properly? sludge in the reservoir could be caused by the coolant sitting there for too long without been replaced. You will need to do a whole system flush when you fix your current problem.

**My00Z28** · 05-25-2011, 09:34 AM

if you have a cracked radiator i would replace that even if its not the problem! and if its leaking from that crack your coolant would never reach correct operating temps and would not show you any type of over heating.... a clog in the radiator would cause over heating but a clog in your heatercore would not, your heat would just suck. IMO i would get it flushed out and see what happens!

**JayTA98** · 05-25-2011, 09:39 AM

Originally Posted by My00Z28

if you have a cracked radiator i would replace that even if its not the problem! and if its leaking from that crack your coolant would never reach correct operating temps and would not show you any type of over heating.... a clog in the radiator would cause over heating but a clog in your heatercore would not, your heat would just suck. IMO i would get it flushed out and see what happens!

Very good point. i had something similar to this but it was my radiator cap. I keep losing radiator fluid but no leaks. So I know you are tight in money but if the radiator is not clogged(which you will need a new one) when you get a chance replace it because of the crack. If will cost you more if the crack gets bigger and leaves your stranded on the side of the road.

**Spaz** · 05-25-2011, 09:52 AM

if i'm not mistaken the LT1 radiator is an upgrade and possibly cheaper...

**Hhammer15** · 05-25-2011, 11:32 AM

@kmdef9: I didn't know the exhaust had a color or even how to check, and I can't do the compression check due to the crack in the radiator.

@jayTA98: Engine fans are turning on and I ruled out the water pump because it was circulating fine when I replaced the thermostat and a sensor (forget what it was called, I think it regulated the coolant temp?) but then randomly it started overheating again which made me think of it being clogged. The coolant is filthy because it is picking up the sludge in the bottom of the plastic resevor. I had it flushed about 3000 miles ago but is there something more advanced I could do after I replace it?

@My00Z28: How do you check for a heatercore clog and can I flush it myself?

@Spaz: Thanks, I'll look into it and get a part number.

So where can I find a "how to" steps guide to replace the radiator and plastic resevor?

**JayTA98** · 05-25-2011, 11:49 AM

Originally Posted by Hhammer15

@kmdef9: I didn't know the exhaust had a color or even how to check, and I can't do the compression check due to the crack in the radiator.

@jayTA98: Engine fans are turning on and I ruled out the water pump because it was circulating fine when I replaced the thermostat and a sensor (forget what it was called, I think it regulated the coolant temp?) but then randomly it started overheating again which made me think of it being clogged. The coolant is filthy because it is picking up the sludge in the bottom of the plastic resevor. I had it flushed about 3000 miles ago but is there something more advanced I could do after I replace it?

@My00Z28: How do you check for a heatercore clog and can I flush it myself?

@Spaz: Thanks, I'll look into it and get a part number.

So where can I find a "how to" steps guide to replace the radiator and plastic resevor?

did you do a whole system flush? or just drained the radiator? you need a whole system flush. If you are doing it yourself you need to remove the block drains as well. For the reservoir just take out the battery and remove the 2 bolts are the top of the battery base. Disconnect the small hole on the left side of the radiator neck. Pull the whole reservoir out. Clean it with water and soap good until you dont see more sludge coming out. Install the reservoir back and fill it up.

Does the coolant looks bad inside the radiator? how many miles the car has? Do you have a SES light on?
Are both fans turning on? I believe one of them turn on at a specific low temp and then the other turn at a specific high temp. Have you noticed if this is happening?

**Hhammer15** · 05-25-2011, 04:19 PM

@JayTA98: I'm not quite sure if they did a whole system flush or not. Even though it was about 3000 miles ago car wise it was over a year ago. Long story short, my clutch system went out (clutch, slave, master) and that was a whole different deal.

Coolant looks crappy even though it's fresh, it's got 122000 miles, no ses light. and both fans are turning on.

stupid question, where are the block drains?

**JayTA98** · 05-25-2011, 06:41 PM

Originally Posted by Hhammer15

@JayTA98: I'm not quite sure if they did a whole system flush or not. Even though it was about 3000 miles ago car wise it was over a year ago. Long story short, my clutch system went out (clutch, slave, master) and that was a whole different deal.

Coolant looks crappy even though it's fresh, it's got 122000 miles, no ses light. and both fans are turning on.

stupid question, where are the block drains?

My guess is they didn't do a whole system flush.

no question is stupid here. There is 2 drains: one behind the alternator area on the block. Its a big allen socket(19mm i believe). The other one is on top of the starter. You can look between the starter and the engine, you will see it. I believe that one is 5/16 but you need it to be at least 6" long.

if you are doing the flush yourself, drain the radiator take the tstat out of the housing and reinstall the housing and hose back. take out the drains by the block. careful with your face, you will get soaked with left over coolant. Once the block drains, reinstall the drains back by hand, dont tighten them yet. Fill the radiator with water. Make sure that the A/C is set to hot so there will be circulation thru the heater core. Start the car and let it run for a few mins. turn the car off and drain the radiator and block again.

Repeat the process until the water comes out clear from the radiator drain and from the block drains. Apply some liquid teflon to the block drains and tighten them down. Re install the tstat in the housing. Pull the reservoir out and wash with water/soap until clean water comes out. Reinstall reservoir. remove the small coolant hose from the engine coolant pipe. This hose is the one connected from the coolant pipe at the engine to the throttle body or if you did the TB bypass mod it will be the hose from the neck of the radiator to the engine pipe. Removing the hose will allow air to escape at the highest point of the engine preventing a bubble in the system.

Once the hose is disconnected slowly pour a 50/50 mix of dexcool. DO NOT MIX COOLANTS. if you are going to change to the green stuff then now is the time. I used dexcool again. Keep an eye at the pipe where you disconnected the small hose. Once coolant starts to pour out then you can stop. reconnect the small hose back to the pipe. Fill the resevoir with straight coolant to proper level.

Start the engine and keep the radiator cap off. If the coolant level drop add more. You will have to wait for the engine to get hot enough for the tstat open. this could take 20 mins. once the stat opens the coolant level will drop. add more to proper level. Put the radiator cap on and check for leaks.

Run the car with A/C in heat for some time. this will help clear any bubbles in the heater core and its hoses. let the car cooldown and check the radiator coolant level. add more if needed. Keep checking the level for at least 2 days.

**Hhammer15** · 05-25-2011, 10:05 PM

Wow, thank you so much. I don't have work tomorrow so I will be getting on top of it first thing in the morning and post any problems I come across. Does it matter at all if my A/C compressor is busted for the heatercore issue?

**JunkyardZ** · 05-26-2011, 08:23 AM

Is the radiator leaking from the crack? If so, it needs to be replaced! If your cooling system has a leak and can't build pressure the water will boil and the car can overheat. So don't go through all the work of properly flushing the coolant if you have a leak. If there are no leaks and the cooling fans work I would suspect head gasket problems or even air in system. I'm not sure about f-bodies but while replacing waterpumps on 5.3 and 6.0 trucks and vans I have seen them have problems getting all the coolant back in and have had to undo a radiator hose to get it filled back up.

**My00Z28** · 05-26-2011, 10:27 AM

Originally Posted by JunkyardZ

Is the radiator leaking from the crack? If so, it needs to be replaced! If your cooling system has a leak and can't build pressure the water will boil and the car can overheat. So don't go through all the work of properly flushing the coolant if you have a leak. If there are no leaks and the cooling fans work I would suspect head gasket problems or even air in system. I'm not sure about f-bodies but while replacing waterpumps on 5.3 and 6.0 trucks and vans I have seen them have problems getting all the coolant back in and have had to undo a radiator hose to get it filled back up.

a leak in the cooling system will not show any of over heating it would actually read low!!! but you will be then over heating the block its self and never see it on the gauge! fixing the radiator is a must if its leaking but more than likely will not solve an overheating problem(unless it is clogged)

**JunkyardZ** · 05-26-2011, 10:46 AM

Originally Posted by My00Z28

if you have a cracked radiator i would replace that even if its not the problem! and if its leaking from that crack your coolant would never reach correct operating temps and would not show you any type of over heating.... a clog in the radiator would cause over heating but a clog in your heatercore would not, your heat would just suck. IMO i would get it flushed out and see what happens!

My bad...I must have missed this post on my first readthrough. No one ever stated what the temp gauge was doing. With a leak in the system you can experience a boil over from lack of pressure in the cooling system which is what he said was going on and I didn't know if that meant the car was acutally overheated(260 degrees)or just boiling at 200-210 degrees from lack of a sealed system. I have seen cooling system leaks cause all kinds of symptoms but can't remember one that caused the gauge to stay cold unless the system is empty and then it goes from cold to hot really fast.

**allbaugh_04** · 05-26-2011, 10:50 AM

A radiator is 90-150 dollars online. Sounds like you should replace it.

It's a cake walk, no worries.

**My00Z28** · 05-26-2011, 10:57 AM

Originally Posted by allbaugh_04

A radiator is 90-150 dollars online. Sounds like you should replace it.

It's a cake walk, no worries.

plus some of the ones you find online still have lifetime warranties(but then u have shipping hassle) when i had my 94 trans am i got one off ebay for $80 with a lifetime warranty!!! worked great!