Engine: T5: Coolant hose popped off, engine overheated.

[stuart bowes]

I'm not convinced there is one single country anywhere that you can claim as a general rule everyone always redlines their cars

amongst one particular community maybe, amongst your group of friends sure but other than that it's a ridiculous sweeping statement

I can only go by what I've seen on this forum as a 'general rule' in the 4 years I've been reading posts and I don't actually recall seeing even one post about someone blowing a head gasket or cracking the block

I may have missed something though, are we talking about standard setups, or where people have had silly remaps

[mcfe]

Originally Posted by T5R92011

This is why you need to throw away your 2.5T engine and replace it with the 2.4 T5 (B5244T5). That very specific engine has the 81mm bore cylinders, with thicker walls, just like the original 2.3 T5 engine.

That B5244T5 engine will also remap to over 300bhp at stage 1, so its a nice alternative replacement engine to the original 2.5T R engine.

There is a case of notoriety for the 2.5T when boosted to 300bhp but the rest of the 5 cylinder engines, in stock form are very reliable engines that will do big miles. In the UK at least, nobody associates the Volvo modular engine with headgasket issues.

I actually have the 140hp(unlocked to 170hp) model and have had nothing but problems(way before I even attempted the unlock). However I am aware of the blocks, I am a very big enthusiast and researched this quite a lot of over the past 1.5 years.

The 2.0,2.3 and 4T5 are the only blocks with 81mm bore and thus can withstand 300hp easily, though it is still good practice to shim them. A shimmed 83mm block has been shown to withstand 400,500hp, provided they are shimmed early before the crack has a chance to form. The other solution is Darton sleeves.

The only difference between 2.5t and 2.4t(and 2.4i NA) is the crank throw which is where the extra 0.1l comes from, other than that the 140hp/170hp, 2.4t, 2.5t blocks are the same(except 4T5).

@stuarts, trust me we are a very car obsessed country, quite regularly we have individuals filming themselves doing at times 250km/h in *a* city that it makes news often. But this is beside the point, we were talking about the unusually high cases of HG/block failure. You say you rarely if at all hear these kinds of things, whereas I said that it happens more often than usual.

Perhaps..just perhaps it is as a user said, environmental + usage. In my country we now regularly have 40+c degree summer. The volvo thermostat opens at 105c, additionally in my country often people have installed aftermarket LPG tanks, LPG and CNG(mind you I have a bifuel model factory fitted with CNG tank) burn hotter than petrol, so you can imagine all this heat may cause premature early failure in some of the cases. But this specifically is just an assumption.

I personally monitor my ECT using custom built software and hardware, I've had the temp displayed on the small display to the left. Just idling, the temp goes from 88c standard to 105c where the thermostat fully opens and the fan kicks in. This drops the temp to 95c where the process repeats itself after a minute. I do not consider this normal, so I will be doing another block test in the future but I have planned several last resorts and that is changing the thermostat and oil cooler. Everything else is new, water pump and radiators.

[V70roma]

Originally Posted by mcfe

I actually have the 140hp(unlocked to 170hp) model and have had nothing but problems(way before I even attempted the unlock). However I am aware of the blocks, I am a very big enthusiast and researched this quite a lot of over the past 1.5 years.

The 2.0,2.3 and 4T5 are the only blocks with 81mm bore and thus can withstand 300hp easily, though it is still good practice to shim them. A shimmed 83mm block has been shown to withstand 400,500hp, provided they are shimmed early before the crack has a chance to form. The other solution is Darton sleeves.

The only difference between 2.5t and 2.4t(and 2.4i NA) is the crank throw which is where the extra 0.1l comes from, other than that the 140hp/170hp, 2.4t, 2.5t blocks are the same(except 4T5).

@stuarts, trust me we are a very car obsessed country, quite regularly we have individuals filming themselves doing at times 250km/h in *a* city that it makes news often. But this is beside the point, we were talking about the unusually high cases of HG/block failure. You say you rarely if at all hear these kinds of things, whereas I said that it happens more often than usual.

Perhaps..just perhaps it is as a user said, environmental + usage. In my country we now regularly have 40+c degree summer. The volvo thermostat opens at 105c, additionally in my country often people have installed aftermarket LPG tanks, LPG and CNG(mind you I have a bifuel model factory fitted with CNG tank) burn hotter than petrol, so you can imagine all this heat may cause premature early failure in some of the cases. But this specifically is just an assumption.

I personally monitor my ECT using custom built software and hardware, I've had the temp displayed on the small display to the left. Just idling, the temp goes from 88c standard to 105c where the thermostat fully opens and the fan kicks in. This drops the temp to 95c where the process repeats itself after a minute. I do not consider this normal, so I will be doing another block test in the future but I have planned several last resorts and that is changing the thermostat and oil cooler. Everything else is new, water pump and radiators.

I do feel a bit for the original poster who may have a slightly leaky head gasket which any decent workshop/garage should be able to diagnose and sort out and now may think it is likely to suffer contant problems.

We seem to have entered some dystopian place where "all Volvos have head gasket issues" and many of the p2 era have "head gasket issues,cracked blocks and depression of the head gasket unto the block because of overheating(aluminium is malleable)"

I am intrigued to know where this place is (is it a secret) I am glad I live in a place (UK) where the overwhelming majority of Volvos do not have head gasket issues and aluminium alloy with many very desirable properties is considered a very good material for cylinder heads on both standard and performance cars

Regarding the "volvo thermostats opens at 105c" none I've ever come across in road cars or marine engines do, usually high 80s/low 90s. Yes the fan probably kicks in around 105c but the thermostat should be fully open way before that.

Regarding 40+c ambient summer temperatures a standard Volvo should happily run all day everyday day at that and more. Of course if you start taking things way beyond their original design parameters all bets are off and failures will obviously become much more common.

[stuart bowes]

Originally Posted by V70roma

... if you start taking things way beyond their original design parameters all bets are off and failures will obviously become much more common...

exactly what I was thinking

intrigued to know from mcfe, with specific regard to your own 140hp model that 'had nothing but problems' before you did any remapping, what those problems were, what sort of mileage are we talking about and was that engine at the time completely standard

genuinely interested because it sounds like we have the same engine and I was at one point considering the remap (although I don't think it would make enough difference in every day driving to warrant the effort tbh)

[mcfe]

Originally Posted by V70roma

I do feel a bit for the original poster who may have a slightly leaky head gasket which any decent workshop/garage should be able to diagnose and sort out and now may think it is likely to suffer contant problems.

We seem to have entered some dystopian place where "all Volvos have head gasket issues" and many of the p2 era have "head gasket issues,cracked blocks and depression of the head gasket unto the block because of overheating(aluminium is malleable)"

I am intrigued to know where this place is (is it a secret) I am glad I live in a place (UK) where the overwhelming majority of Volvos do not have head gasket issues and aluminium alloy with many very desirable properties is considered a very good material for cylinder heads on both standard and performance cars

Regarding the "volvo thermostats opens at 105c" none I've ever come across in road cars or marine engines do, usually high 80s/low 90s. Yes the fan probably kicks in around 105c but the thermostat should be fully open way before that.

Regarding 40+c ambient summer temperatures a standard Volvo should happily run all day everyday day at that and more. Of course if you start taking things way beyond their original design parameters all bets are off and failures will obviously become much more common.

Constant problems would be suffered IF the block is not machined flat with the head, since they do get out of spec, the spec is not published anywhere, but flat is better than having > 0.002 thou(in inches) warpage.

Head warpage + block warpage = total warpage.

As for the thermostat, I have had many issues, burst hoses, burst heater cores and so forth which required me to refill the system each time, and the thermostat always fully opened at exactly 105c where I would see the water drain around allowing me to fill the coolant reservoir once again, incidentally the fan kicks in at 105c as well. This can be changed with a reprogram.

The failures I experienced were with the system at stock. Bad HG, led to a burst radiator, at which point I took off the head and sent it for machining and then measured 0.05mm and more(up to 0.07mm) of warpage, which is 0.0025 or ~0.003 thou respectively, not terrible but not great either. I did not have the tools to get it out at the time so I did not do that, but in hindsight, bad idea. 8 months after that I started noticing anomalies once more, which were firm hoses and a burst heater core. The heater core did not burst while driving, but while idling for 10 minutes on a parking lot, on a cool 10c day. I had the heat on at full blast to keep warm. The only thing I remember is hissing and then steam behind the dashboard.

@stuart, well the common mileage on these cars over here is at least 250-300k KM or 150-200k miles. The issues I had BEFORE I did any HG change or remapping was leaky thermostat, which is why I replaced it with a brand new one. Then I started noticing that every time I would unscrew the cap the coolant wanted to rush out. But sometimes it didn't, so I deduce I need a new cap and replace it but the problem persisted. Alarms were ringing at this point and I go and do a block test, the mixture turned green but not immediately.

I started calling shops, and I don't mean one or two, even my regular mechanic said at this point I should junk the car. He explained all the things I mentioned above. Not satisfied with this answer I called mechanics from across the country, and those specifically working only with Volvos, the moment they heard BIFUEL Volvo is the moment they told me to look for a new motor as this one is either cracked, warped or the gasket has sunk unto the block(like an outline). They also said my options are a new engine or sleeves. And quoted a price twice as expensive as the price I bought the car for. What do I do? I drive the car like this for a while evaluating my options.
Meanwhile I measured the compression at the time with the issues. Cyl 1-3 had lower compression(like 150-160 psi) which is where the problem likely lied, as it is that particular location, where I measured the most warpage, especially diagonally, almost as if the cylinders had leaned back.

One day I am learning about the car(specifically the 140hp limiter), it is a cold 0c night(midnight to be exact), I go to the car, start it up, warm up the engine to working temp, and rev the car to 5k rpm for 5 or a bit more seconds in order to observe how the throttle body behaves. The car shuddered and steam rose out of the engine bay. Coolant was running down the car. I immediately stop the car and that is how my adventures began. Later I saw a golf ball sized hole on the opposite side of the radiator where the upper hoses connects to it.

Once I semi rebuilt the engine, which was just the head I had no issues for a while. Then I finally managed to crack a lot of things related to the limiter and fully unlocked the car to 170hp. Just like a stock 170hp motor

The acceleration was better, harder. Why? Because the throttle was fully opening this time but only after 4k rpm or 4500rpm thereabout.

Now, stuart, one thing should be noted is that the NA engines have a flat spot on the torque curve between 2 and 3k rpm. It is either the camshaft valve overlap for emissions purposes, or a serious intake resonance(where the air charge hits the closed valve and oscillates back and forth reducing the overall velocity of the charge). I personally want to attempt to fix this. The point is, the unlock while safe, provides no benefit below 4k rpm.

Overall it is worth it, to me, but I have a heavy foot and do see myself above 4500 RPM, but not recently due to the issues I outlined(exploded heater core matrix *after* the HG change and firm hoses).


@v70roma
As I said before, I notice changes at 105c, maybe I have a defective thermostat. I will replace it, as well as the cap with a Volvo original one as well as a new oil cooler just in case I am getting pressure from that unit. I have also noticed at times, oil floating around in the coolant tank, when I have cleaned it out many times after the HG change, as well as using special cleaner additives on the coolant system.

This is my last resort. And to summarize, when we exclude all other components that I have trouble with, such as my AW55, the most persistent issue has been the coolant system.

[Verracciii]

Quick update on my overheated 2001 S60 2.0L.

On the first start after the overheating, I heard a ticking noise on cold and my coolant kept going down. The ticking noise went away when warm. The engine felt a bit rougher.

Now after a couple of days, there still is a slight ticking until it is warmer. However, before the overheating, I had a bit of white smoke. Immediately after overheating, I had white smoke (presumably coolant). However, now, after some time, there is no more white smoke at all any more and my coolant does not decrease - which has me baffled.

While I am sure there is some sort of damage, the car seems to run okay.

I am (controversially) considering using some head gasket sealer. I only need this car to last me until the end of this summer when I move to university. While I don't actually notice any signs of a head gasket leak, I think this still might be worth a shot?

[Kev0607]

Originally Posted by Verracciii

Quick update on my overheated 2001 S60 2.0L.

On the first start after the overheating, I heard a ticking noise on cold and my coolant kept going down. The ticking noise went away when warm. The engine felt a bit rougher.

Now after a couple of days, there still is a slight ticking until it is warmer. However, before the overheating, I had a bit of white smoke. Immediately after overheating, I had white smoke (presumably coolant). However, now, after some time, there is no more white smoke at all any more and my coolant does not decrease - which has me baffled.

While I am sure there is some sort of damage, the car seems to run okay.

I am (controversially) considering using some head gasket sealer. I only need this car to last me until the end of this summer when I move to university. While I don't actually notice any signs of a head gasket leak, I think this still might be worth a shot?

If there's no sign of a head gasket issue or cooling problem now, there's little point putting that stuff in. Its not going to achieve anything.

Just keep your eye on the coolant level and the temp gauge. Carry some coolant or water in the boot just in case.

[stuart bowes]

if it's just to the end of summer why not just keep a bottle of water in the boot and top up every couple of days, pouring some random sealer stuff in there might cause even more issues

[Clan]

Originally Posted by keith240

Well I've never had any head gasket issues on petrol engined S80s (current one is 20 years old with 180,000 miles) or indeed an XC90 with a 2.5t. I have never heard mention of any such weakness at my local specialist either. So from personal experience I would say it is not true/fact.

same with me in my 47 year experience working on volvos Professionally. Some people do neglect and abuse their Volvo's engines now though !