Low side with high pressure and High side with 150psi

[Notnilc20]

Car is a 2009 volvo s40 rurbo. ac compressor cycles on and off. Stays on for about 5 seconds and shuts off for about 15 seconds and repeats. When I hook the manifold gauges up while car is off, the low side was over 300psi and the high side was around 150psi. Then I start the car and turn the ac on. The low side drops to about 100psi and the high side shoots up to over 400psi. then the safety switch kicks on and shuts the compressor off. then this basically jist repeats. What could it be? Thank. Car is an 2009 volvo s40 turbo. thank you.

[Diametric]

That vehicle uses R134a refrigerant.
Pressures when the vehicle is not running should be very close to the Ambient temperature in F at your location.

300psi with the vehicle not running might might indicate an overcharge condition.
Low side at 100psi when running sounds too high to me.
But the cycling sounds ok. Is there cold air coming from the vents when the AC is on?

There could be other issues but I would recover (please don't vent to atmosphere) some R134a to bring those readings down. It could also be your gauges are not reading correctly or you have the knobs partially open.

Tim and JohnHere are professionals in this field and I would go by their advice. I do a lot of AC stuff on my own vehicles but have had no formal training although I am EPA certified for commercial refrigerant purchase and recovery and study AC refrigeration on my own.

[JohnHere]

The problem might be elsewhere, but right off the bat, it sounds like a gross overcharge to me.

Has this system ever been serviced?

[Notnilc20]

He said he never had it serviced and ac was running perfectly but then he left car running amd came back 5 minutes later and the ac was not blowing cold air. Ac compressor kicks on for a second then goes off.

[JohnHere]

He said he never had it serviced and ac was running perfectly but then he left car running amd came back 5 minutes later and the ac was not blowing cold air. Ac compressor kicks on for a second then goes off.

Then I presume no sealer was introduced into the system.

As a first step, I suggest recovering the charge to determine how much refrigerant is in there. At the same time, I would pull the OT and examine it. If it's full of black gunk mixed with metallic "glitter," then we have bigger, more expensive problems that point to an internally disintegrating compressor. If so, that situation would require replacing the compressor assembly, condenser, OT, R/D, and flushing the rest.

[ИльяPi]

Для встречи разговорного клуба выбираю тему самостоятельных путешествий. Мы не продаём экскурсии и не составляем настоящий маршрут. Задача проще: научиться задавать уточняющие вопросы, когда читаешь чужое описание путешествия. Ищу компактный пример, который удобно обсуждать вместе. Участники будут работать парами и сравнивать свои вопросы. В поисковой подборке встретилось сочетание михаил шварц путешествия — ссылку пока рассматриваю только как возможный материал занятия. Прежде чем что-либо раздавать, выберу небольшой фрагмент и проверю, подходит ли он нашей группе. Хотелось бы отделить личные впечатления автора от сведений, которые читатель должен уточнить самостоятельно. Одна пара могла бы выписать вопросы о дороге. Другой паре предложу разобрать последовательность действий. Также отметим места, которым нужна дата или пояснение. Уровень подготовки у всех разный, поэтому важно, чтобы участник мог объяснить свой вопрос обычными словами и показать, какой фрагмент текста заставил его об этом задуматься. Какое задание помогает новичкам читать такие материалы внимательно, но не превращает встречу в экзамен? Буду рад короткому упражнению для совместного обсуждения.