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

[Verracciii]

Hey,

Currently still in a bit of shock. I went back into my car after a bit of shopping only to turn it on and it started like the battery was dead. I then saw that the coolant temp was at the max. I immediately turned off the engine. The coolant hose from the radiator to the engine head popped off. We had trimmed the hose after it split from a corroded hose clamp about a month ago. I popped it on and fastened and filled it with coolant. I then waited around 40 minutes and then turned on the engine with a starter pack, it was only around a 40-second drive home. Temp seemed normal and I had air heating turned to max.

I am just now stressed and would appreciate any words. I may have a slight head gasket leak possibly. Smoke from exhaust but it's not thick. I am just paranoid about driving it again.

I bought the car from my dad and he's always left the coolant reservoir slightly opened to relieve pressure. Yesterday I closed it fully and then this issue happened, could this be a causation?

[OldFishtank]

I suppose it's possible that is the cause for excessive pressure. Get a new cap and give it a whirl!

[mcfe]

Firstly these cars, all of the Volvos, turbo or otherwise often have headgasket issues. Unfortunately they often have warped blocks as well. The turbo petrols also suffer from cracked blocks depending on some things.

Here are a list of possible causes of pressure in the coolant system just from my own observation.

Oil cooler leak
Head gasket(+ inevitably warped block)
Cracked block(thin cylinders in most engines except the 2.3 and 2.0 engines and B5244T5)
Coolant reservoir cap
Thermostat
Failed engine fan(will not cool down car when it reaches a higher temp idling).

Here is some Volvo math since you said temp gauge was at max. The temp gauge of ALL volvos does not move between the range 80-120c, it stays strong vertical.

After 121c or 125c it starts to rapidly climb. Since you drove with less or no coolant and your temp gauge was at max, you likely exceeded 130c or more. At those temps I'd imagine the damage is done. Warped head + warped block.

Time for a block test. If there is head gasket failure, you need to machine both the head and block flat.

Also yes, you tightened it down and the pressure could not escape. Bear in mind that the coolant tank is designed to keep a pressure of 21psi or 1.5 bar. This is because at normal air pressure 100c water boils, but not so under pressure.
If there is excess pressure the cap cannot relieve(or it is broken) it would cause issues.

[GrahamBrown1]

Originally Posted by mcfe

Firstly these cars, all of the Volvos, turbo or otherwise often have headgasket issues. Unfortunately they often have warped blocks as well. The turbo petrols also suffer from cracked blocks depending on some things.

Here are a list of possible causes of pressure in the coolant system just from my own observation.

Oil cooler leak
Head gasket(+ inevitably warped block)
Cracked block(thin cylinders in most engines except the 2.3 and 2.0 engines and B5244T5)
Coolant reservoir cap
Thermostat
Failed engine fan(will not cool down car when it reaches a higher temp idling).

Here is some Volvo math since you said temp gauge was at max. The temp gauge of ALL volvos does not move between the range 80-120c, it stays strong vertical.

After 121c or 125c it starts to rapidly climb. Since you drove with less or no coolant and your temp gauge was at max, you likely exceeded 130c or more. At those temps I'd imagine the damage is done. Warped head + warped block.

Time for a block test. If there is head gasket failure, you need to machine both the head and block flat.

Also yes, you tightened it down and the pressure could not escape. Bear in mind that the coolant tank is designed to keep a pressure of 21psi or 1.5 bar. This is because at normal air pressure 100c water boils, but not so under pressure.
If there is excess pressure the cap cannot relieve(or it is broken) it would cause issues.

I’m intrigued how you form the opinion that all Volvos often have head gasket issues. I have owned many as have many others and not had any head gasket issues. The petrols of this era I thought were extremely reliable. The only block issue i have heard about is on the R models but they are a complete different beast. Just out of interest?

[mcfe]

Originally Posted by GrahamBrown1

I’m intrigued how you form the opinion that all Volvos often have head gasket issues. I have owned many as have many others and not had any head gasket issues. The petrols of this era I thought were extremely reliable. The only block issue i have heard about is on the R models but they are a complete different beast. Just out of interest?

The only reason I form it, is because it is true. I have communicated with many volvo owners of the P2 era, who had this kind of problem. And moreso when I myself had issues and contacted multiple shops who did not want to touch a volvo with a ten foot pole, because of head gasket issues, cracked blocks and depression of the headgasket unto the block because of overheating(aluminum is malleable).

When I had my radiator literally explode because of overpressure I took off the head sent it to get machined, 0.14mm were taken off the head. The block measured 0.05-0.07mm warpage, it should be closer to 0. I did not machine the block.

After reassembling I drove nearly 8 or so months before the next thing that went was the heater core matrix which exploded whilst idling. My hoses are once more becoming stiff. I plan to replace the cap with a Volvo original one and replace the oil cooler and thermostat(again) and if they still become stiff or I notice more oddities, I will know it's the block.

The R blocks are the same as the 140/170hp blocks. The difference is crank and pistons and possibly conrods(the NA 170hp versions share the same conrods as 4T3). Everything else is identical, down to the bore size which is where the problem lies. At 300hp it is guaranteed to crack. At 250 you will get cracks after some time but may last longer if you don't WOT. At 210 it is less likely, but not impossible.
The reason is simple, open deck design with thin cylinder walls.

[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 wiuld say it is not true/fact.

[mcfe]

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 wiuld say it is not true/fact.

Around half a year ago or more I spoke with a guy who was looking for a 2.5t block(210hp) on his XC90. It was cracked. However it is possible he purchased it like that, and the previous owner could have had a tune raising boost and giving all the gas. In my country it is considered normal to redline the cars(regardless of brand).

When reputable shops over here would hear about Volvo and re-sleeving they say the following: either Darton or not at all. Apparently if it's a regular sleeve they would often drop. I am not a machinist, I cannot say why.

[GrahamBrown1]

Originally Posted by mcfe

The only reason I form it, is because it is true. I have communicated with many volvo owners of the P2 era, who had this kind of problem. And moreso when I myself had issues and contacted multiple shops who did not want to touch a volvo with a ten foot pole, because of head gasket issues, cracked blocks and depression of the headgasket unto the block because of overheating(aluminum is malleable).

When I had my radiator literally explode because of overpressure I took off the head sent it to get machined, 0.14mm were taken off the head. The block measured 0.05-0.07mm warpage, it should be closer to 0. I did not machine the block.

After reassembling I drove nearly 8 or so months before the next thing that went was the heater core matrix which exploded whilst idling. My hoses are once more becoming stiff. I plan to replace the cap with a Volvo original one and replace the oil cooler and thermostat(again) and if they still become stiff or I notice more oddities, I will know it's the block.

The R blocks are the same as the 140/170hp blocks. The difference is crank and pistons and possibly conrods(the NA 170hp versions share the same conrods as 4T3). Everything else is identical, down to the bore size which is where the problem lies. At 300hp it is guaranteed to crack. At 250 you will get cracks after some time but may last longer if you don't WOT. At 210 it is less likely, but not impossible.
The reason is simple, open deck design with thin cylinder walls.

Were are you from? Perhaps this is a local issue to you, as this is mainly a UK forum it’s not something we see regular over here I’m sure of it. Usage, fuels, environment may well be a factor who knows. Certainly strange.

[T5R92011]

Originally Posted by mcfe

The only reason I form it, is because it is true. I have communicated with many volvo owners of the P2 era, who had this kind of problem. And moreso when I myself had issues and contacted multiple shops who did not want to touch a volvo with a ten foot pole, because of head gasket issues, cracked blocks and depression of the headgasket unto the block because of overheating(aluminum is malleable).

When I had my radiator literally explode because of overpressure I took off the head sent it to get machined, 0.14mm were taken off the head. The block measured 0.05-0.07mm warpage, it should be closer to 0. I did not machine the block.

After reassembling I drove nearly 8 or so months before the next thing that went was the heater core matrix which exploded whilst idling. My hoses are once more becoming stiff. I plan to replace the cap with a Volvo original one and replace the oil cooler and thermostat(again) and if they still become stiff or I notice more oddities, I will know it's the block.

The R blocks are the same as the 140/170hp blocks. The difference is crank and pistons and possibly conrods(the NA 170hp versions share the same conrods as 4T3). Everything else is identical, down to the bore size which is where the problem lies. At 300hp it is guaranteed to crack. At 250 you will get cracks after some time but may last longer if you don't WOT. At 210 it is less likely, but not impossible.
The reason is simple, open deck design with thin cylinder walls.

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.

[Georgeandkira]

"In my country it is considered normal to redline the cars(regardless of brand)."

Where is this?