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Hey everyone!
I have an 02 Monte Carlo with the 3.4L engine and 124,000 miles on it. The wonderful intake gaskets have gone to crap, so it is pumping all the oil into the coolant. I am curious to know how long the head gaskets are known to last on these engines. Should I spend the extra money and time to replace them as long as I have it torn down that far? Or would it likely be a waste of both?
Thanks in advance!
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Did that job on my brothers 2001 Monte Carlo 3400 a few months ago.
We came to the same choice.
We decided we dug down that far …..
All that was needed was to remove the head bolts, rockers, push rods and release the exhaust pipe, which was a matter of 20 extra minutes and the cost of new head bolts and head gaskets..
We left the cross over exhaust pipe in place and removed both heads as a single assembly.
Got to inspect and clean the heads and inspect for flatness, and clean some gunk out of the water jacket due to dexacool.
Make your life easy, remove the front engine mounts and ratchet strap the engine forward to get some extra working room by the firewall.
Might also consider removing the hood.As to how long will the original head gaskets last ……
To quote… “how long is your shadow”
JMHO here…..
Some will say only do what is needed.
But much akin to changing a timing belt, many will replace idlers, tensioners and the water pump (if it’s buried in there ) just because you’ve dug that deep.I agree on fixing what is broke only. I have the 99 monte carlo with the 3.1. These are known for bad intake gaskets due to the plastic OEM gaskets. You could do some test for head gasket assessment prior however unless you overheated, you are probably ok. Mine has 160 K replaced intake gaskets and never a head problem.
[quote=”college man” post=183519]just fix whats broke. ;)[/quote]
Agreed.
While I agree that replacing “targets of opportunity” is a good practice, taking the cylinder heads off because you have the intake off is excessive and opening yourself up to way more problems. By that logic, if you have the heads off already you might as well just pull the engine and rebuild it while you have it apart.
[i]college man wrote:
just fix whats broke. 😉Agreed.
While I agree that replacing “targets of opportunity” is a good practice, taking the cylinder heads off because you have the intake off is excessive and opening yourself up to way more problems. By that logic, if you have the heads off already you might as well just pull the engine and rebuild it while you have it apart. [/i]
Really???? …..REALLY???????
I’m sorry, but how do you come to that conclusion?.
Following you train of thought:
Every Subaru owner, or any vehicle owner, would be rebuilding their engines every time they lost a head gasket ( which is quite common..)Once the upper and lower intake are removed, head gaskets are a relatively simple process.
As to why go the the little extra effort:
One of many examples……..
[color=#00bbff][i]05 Impala 3.4 146,000 miles, had the intakes replaced at 105,000. I was driving to visit my grandpa, about 2.5 hours away from home and all the sudden strong antifreeze smell in the cabin, what the f***, tell the wife to pull over and while pulling over car begins to overheat so I have her kill the engine. I get out and look underneath and antifreeze is pouring out the rear of the engine, couldn’t get a real good look from the side of the highway. Look in the overflow tank and its full of foamy bubbles.. After about 10 minutes I have her start the car, white smoke and dexcool pouring out the tailpipe. Called for a tow to the nearest auto repair I can find. Upon arriving I tell the mechanic what happened, and we looked over the engine, intakes were good, oil was still clean. He could tell that I took care of my car which I have. Just got a call this morning, it’s the head gasket.. $1500 to fix it.
[/i][/color]
Everyone is entitled to do as they please ….
But in this situation….
Considering the minimal amount of parts and labor added to the work already being done at the time.
The possibility of having to do the work again and have it cost 2 X + is really a easy call.Thanks to everyone for their input!
I have a few more questions. I have never had a cam in block engine before. So does that mean that if I have to pull the heads, there is no timing belt/chain to mess with?
Also, lets say I decide not to do the head gaskets right now and they go in 20,000 miles. Would the new intake gaskets that I’m going to install be re-usable? Or am I looking at buying everything all over again?
The guy I had look at it to help me confirm that it is oil in the coolant said that it is likely a cracked block or head because of the fact that it would be hard to be pushing oil into the coolant when the cooling system is under pressure. I know that’s something I’ll have to figure out once I take it apart this weekend, but what’s everyone’s general opinion on that school of thought?
Thanks to everyone for their input!
I have a few more questions. I have never had a cam in block engine before. So does that mean that if I have to pull the heads, there is no timing belt/chain to mess with?
No, head removal does not involve anything with the timing chain
Also, lets say I decide not to do the head gaskets right now and they go in 20,000 miles. Would the new intake gaskets that I’m going to install be re-usable? Or am I looking at buying everything all over again?
You could attempt to re-use the gaskets, but that is a bad gamble at best.
The guy I had look at it to help me confirm that it is oil in the coolant said that it is likely a cracked block or head because of the fact that it would be hard to be pushing oil into the coolant when the cooling system is under pressure. I know that’s something I’ll have to figure out once I take it apart this weekend, but what’s everyone’s general opinion on that school of thought?
[color=#00bbff]I wouldn’t be too sure about your mechanics diagnostics.
Considering the block is cast iron and the heads aluminum …..
A bad intake gasket can allow oil seepage.
Keep something in mind about what your mechanic told you:[/color]
” it would be hard to be pushing oil into the coolant when the cooling system is under pressure.”
[color=#00bbff]Lets see..
Cooling system pressure is somewhere around 14.5 – 17 psi
Oil pressure, somewhere say between 20 – 40 + psi.
Simple math tells you higher pressure will migrate to lower pressure.
Also, is there evidence that coolant is in the oil?
Judging from what you’ve stated, I’d be more inclined to believe a bad gasket or possibly a warped head first before a cracked head or block.[/color]Thanks ALOT for that info! Makes me feel much better! And no, there is no evidence of coolant in the oil, just a LOT of oil in the coolant! Like I said, I’ll figure it out when I get it apart but everything I’ve read says the same as you: a cracked anything on these engines is very unlikely. Probably just wanted to charge me for the short block and engine replacement…
I have had to drive this car this way half an hour each way on the highway every day of this week till the parts arrive and I have the time to repair it. What’s the worst that could’ve happened to it? I’m hoping just a really messy cooling system that has to be flushed multiple times?
Might I suggest:
Before you start the job:
Get a Prestone flush kit and install it.
Run a hose for a bit to clean as much gunk out of the cooling system as possible.
Then ( and I know this will sound crazy ) add DAWN dish washing soap into the cooling system and run that through for a few minutes.
Drain everything ( might try some compressed air to get as much out of the block as possible)Do the repair work.
One suggestion:
If you do replace the head gaskets, jack the car up and un-bolt the exhaust pipe first.
Once you start cracking the engine open you really do not want to crawl under the car when it is dripping fluids.
Another thought:
Get to Harbor Freight and buy one of their 5 x 7 cheap traps and spread it open under the car.
Hopefully that will catch most of the mess and afterwards you can just toss the whole thing in the trash.
Now add water and more DAWN soap.
I did this several times and cleaned out all the oil.
Lastly fill with antifreeze and distilled water.Side note if you pull the heads:
Watch for the 2 guide pins on each side of the block, they may come out with the heads (easy to tap them back into the block )
Pay close attention on how the head gaskets are on the engine.
You do not want to install the new ones upside down or backwards.
BTW spoiler alert:
You need to remove all the push rods (keep them in the order they were removed!!!! ) to replace the lower intake manifold.
400 – 600 wet / dry sand paper and WD-40 works wonders to clean the mating surfaces.
Green Scotch Brite and WD – 40 to clean the tops of the pistion ( let the WD – 40 soak for a while ) make sure to blow / wipe out any debris, then wet the cylinder walls with the WD – 40
Lint free shop towels (a lot of them!!!!)
Use a machinist straight edge and feeler gauges to check for flatness on both the heads and block.unless your seeing considerable drop in oil or to much oil in coolant where it is heating, youll be fine for a week. If you notice the prior said, stop and check coolant. Keep eye on oil and be prepared to flush coolant and change oil after job anyways.
Thanks again for all the help everyone!
In the interest of planning, couple more questions for ya.
Would it be of any advantage to flush the system out without starting the engine before I take things apart and then flush again after job? Or should I just wait till after? My thinking was if I don’t flush before tear down that it’ll be a totally disgusting mess taking things apart.
Also, after all this oil has gone through the cooling system, is it likely that it had any effect on the radiator hoses? Just wondering how much I should really replace after all this trauma to the engine.
Thanks again for all the help everyone!
In the interest of planning, couple more questions for ya.
Would it be of any advantage to flush the system out without starting the engine before I take things apart and then flush again after job? Or should I just wait till after? My thinking was if I don’t flush before tear down that it’ll be a totally disgusting mess taking things apart.
[color=#00bbff]Drain as much coolant as possible first, then if you install the flush kit, just run a garden hose on it.
If your leaking oil into the coolant, no sense to try flushing the system with the engine running.
Once you complete the work, do a fresh oil and filter change and a through flushing of the coolant system[/color]
Also, after all this oil has gone through the cooling system, is it likely that it had any effect on the radiator hoses? Just wondering how much I should really replace after all this trauma to the engine.
[color=#00bbff]If the hoses are relatively new and the oil seep age has only recently started you should be ok.
On the other side of the coin, if the hoses are old… might be wise to replace them.
May want to inspect your belts also.[/color]
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